boost: Fixes Boost.Math build for arm_xscale

This commit adds a new patch which fixes build issue with Boost.Math.
Issue is described in upstream PR boostorg/math#684 [1]

[1]: https://github.com/boostorg/math/pull/684

Signed-off-by: Carlos Miguel Ferreira <carlosmf.pt@gmail.com>

libs/boost/patches/020-math.patch

@@ -0,0 +1,178 @@
+--- a/boost/math/special_functions/detail/bernoulli_details.hpp
++++ b/boost/math/special_functions/detail/bernoulli_details.hpp
+@@ -360,7 +360,7 @@ public:
+          return out;
+       }
+ 
+-      #ifndef BOOST_HAS_THREADS
++      #if !defined(BOOST_HAS_THREADS) || defined(BOOST_MATH_BERNOULLI_UNTHREADED)
+       //
+       // Single threaded code, very simple:
+       //
+@@ -382,6 +382,8 @@ public:
+          *out = (i >= m_overflow_limit) ? policies::raise_overflow_error<T>("boost::math::bernoulli_b2n<%1%>(std::size_t)", 0, T(i), pol) : bn[i];
+          ++out;
+       }
++      #elif defined(BOOST_MATH_NO_ATOMIC_INT)
++      static_assert(sizeof(T) == 1, "Unsupported configuration: your platform appears to have no atomic integers.  If you are happy with thread-unsafe code, then you may define BOOST_MATH_BERNOULLI_UNTHREADED to suppress this error.");
+       #else
+       //
+       // Double-checked locking pattern, lets us access cached already cached values
+@@ -464,7 +466,7 @@ public:
+          return out;
+       }
+ 
+-      #ifndef BOOST_HAS_THREADS
++      #if !defined(BOOST_HAS_THREADS) || defined(BOOST_MATH_BERNOULLI_UNTHREADED)
+       //
+       // Single threaded code, very simple:
+       //
+@@ -494,6 +496,8 @@ public:
+          }
+          ++out;
+       }
++      #elif defined(BOOST_MATH_NO_ATOMIC_INT)
++      static_assert(sizeof(T) == 1, "Unsupported configuration: your platform appears to have no atomic integers.  If you are happy with thread-unsafe code, then you may define BOOST_MATH_BERNOULLI_UNTHREADED to suppress this error.");
+       #else
+       //
+       // Double-checked locking pattern, lets us access cached already cached values
+@@ -555,7 +559,7 @@ private:
+    // The value at which we know overflow has already occurred for the Bn:
+    std::size_t m_overflow_limit;
+ 
+-   #ifdef BOOST_HAS_THREADS
++   #if defined(BOOST_HAS_THREADS) && !defined(BOOST_MATH_NO_ATOMIC_INT)
+    std::mutex m_mutex;
+    atomic_counter_type m_counter, m_current_precision;
+    #else
+--- a/boost/math/tools/atomic.hpp
++++ b/boost/math/tools/atomic.hpp
+@@ -16,27 +16,27 @@
+ namespace boost {
+    namespace math {
+       namespace detail {
+-#if ATOMIC_INT_LOCK_FREE == 2
++#if (ATOMIC_INT_LOCK_FREE == 2) && !defined(BOOST_MATH_NO_ATOMIC_INT)
+          typedef std::atomic<int> atomic_counter_type;
+          typedef std::atomic<unsigned> atomic_unsigned_type;
+          typedef int atomic_integer_type;
+          typedef unsigned atomic_unsigned_integer_type;
+-#elif ATOMIC_SHORT_LOCK_FREE == 2
++#elif (ATOMIC_SHORT_LOCK_FREE == 2) && !defined(BOOST_MATH_NO_ATOMIC_INT)
+          typedef std::atomic<short> atomic_counter_type;
+          typedef std::atomic<unsigned short> atomic_unsigned_type;
+          typedef short atomic_integer_type;
+          typedef unsigned short atomic_unsigned_type;
+-#elif ATOMIC_LONG_LOCK_FREE == 2
++#elif (ATOMIC_LONG_LOCK_FREE == 2) && !defined(BOOST_MATH_NO_ATOMIC_INT)
+          typedef std::atomic<long> atomic_unsigned_integer_type;
+          typedef std::atomic<unsigned long> atomic_unsigned_type;
+          typedef unsigned long atomic_unsigned_type;
+          typedef long atomic_integer_type;
+-#elif ATOMIC_LLONG_LOCK_FREE == 2
++#elif (ATOMIC_LLONG_LOCK_FREE == 2) && !defined(BOOST_MATH_NO_ATOMIC_INT)
+          typedef std::atomic<long long> atomic_unsigned_integer_type;
+          typedef std::atomic<unsigned long long> atomic_unsigned_type;
+          typedef long long atomic_integer_type;
+          typedef unsigned long long atomic_unsigned_integer_type;
+-#else
++#elif !defined(BOOST_MATH_NO_ATOMIC_INT)
+ #  define BOOST_MATH_NO_ATOMIC_INT
+ #endif
+       } // Namespace detail
+--- a/libs/math/test/Jamfile.v2
++++ b/libs/math/test/Jamfile.v2
+@@ -121,6 +121,13 @@ test-suite special_fun :
+ 
+    [ run hypot_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework ]
+    [ run pow_test.cpp ../../test/build//boost_unit_test_framework ]
++   [ run ccmath_sqrt_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_isinf_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_isnan_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_abs_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_isfinite_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_isnormal_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
++   [ run ccmath_fpclassify_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
+    [ run log1p_expm1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework  ]
+    [ run powm1_sqrtp1m1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework  ]
+    [ run special_functions_test.cpp ../../test/build//boost_unit_test_framework  ]
+@@ -870,6 +877,7 @@ test-suite mp :
+ ;
+ 
+ test-suite misc :
++   [ run header_deprecated_test.cpp ]
+    [ run threading_sanity_check.cpp ]
+    [ run test_tr1.cpp
+    ../build//boost_math_tr1
+@@ -1137,6 +1145,9 @@ test-suite misc :
+ 
+ #   [ run __temporary_test.cpp test_instances//test_instances : : : <test-info>always_show_run_output <pch>off ]
+    [ compile test_no_long_double_policy.cpp ]
++   [ compile bernoulli_no_atomic_d.cpp ]
++   [ compile bernoulli_no_atomic_mp.cpp ]
++   [ compile-fail bernoulli_no_atomic_fail.cpp ]
+ ;
+ 
+ test-suite interpolators :
+@@ -1163,6 +1174,7 @@ test-suite interpolators :
+    [ run quintic_hermite_test.cpp  : : :  [ requires cxx17_if_constexpr cxx17_std_apply ]  [ check-target-builds ../config//has_float128 "GCC libquadmath and __float128 support" : <linkflags>-lquadmath ] ]
+    [ run cubic_hermite_test.cpp  : : :  [ requires cxx17_if_constexpr cxx17_std_apply ]  [ check-target-builds ../config//has_float128 "GCC libquadmath and __float128 support" : <linkflags>-lquadmath ] ]
+    [ run bilinear_uniform_test.cpp  : : : [ requires cxx17_if_constexpr cxx17_std_apply ]  ]
++   [ run bezier_polynomial_test.cpp  : : : [ requires cxx17_if_constexpr cxx17_std_apply ]  [ check-target-builds ../config//has_float128 "GCC libquadmath and __float128 support" : <linkflags>-lquadmath ] ]
+    [ run catmull_rom_test.cpp ../../test/build//boost_unit_test_framework : : : <define>TEST=1 [ requires cxx11_hdr_array cxx11_hdr_initializer_list ] : catmull_rom_test_1 ]
+    [ run catmull_rom_test.cpp ../../test/build//boost_unit_test_framework : : : <define>TEST=2 [ requires cxx11_hdr_array cxx11_hdr_initializer_list ] : catmull_rom_test_2 ]
+    [ run catmull_rom_test.cpp ../../test/build//boost_unit_test_framework : : : <define>TEST=3 [ requires cxx11_hdr_array cxx11_hdr_initializer_list ] : catmull_rom_test_3 ]
+--- /dev/null
++++ b/libs/math/test/bernoulli_no_atomic_d.cpp
+@@ -0,0 +1,14 @@
++//  (C) Copyright John Maddock 2021.
++//  Use, modification and distribution are subject to the
++//  Boost Software License, Version 1.0. (See accompanying file
++//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
++
++#define BOOST_MATH_NO_ATOMIC_INT
++
++#include <boost/math/special_functions/bernoulli.hpp>
++#include "compile_test/test_compile_result.hpp"
++
++void compile_and_link_test()
++{
++   check_result<double>(boost::math::bernoulli_b2n<double>(4));
++}
+--- /dev/null
++++ b/libs/math/test/bernoulli_no_atomic_fail.cpp
+@@ -0,0 +1,15 @@
++//  (C) Copyright John Maddock 2021.
++//  Use, modification and distribution are subject to the
++//  Boost Software License, Version 1.0. (See accompanying file
++//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
++
++#define BOOST_MATH_NO_ATOMIC_INT
++
++#include <boost/math/special_functions/bernoulli.hpp>
++#include <boost/multiprecision/cpp_bin_float.hpp>
++#include "compile_test/test_compile_result.hpp"
++
++void compile_and_link_test()
++{
++   check_result<boost::multiprecision::cpp_bin_float_50>(boost::math::bernoulli_b2n<boost::multiprecision::cpp_bin_float_50>(4));
++}
+--- /dev/null
++++ b/libs/math/test/bernoulli_no_atomic_mp.cpp
+@@ -0,0 +1,16 @@
++//  (C) Copyright John Maddock 2021.
++//  Use, modification and distribution are subject to the
++//  Boost Software License, Version 1.0. (See accompanying file
++//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
++
++#define BOOST_MATH_NO_ATOMIC_INT
++#define BOOST_MATH_BERNOULLI_UNTHREADED
++
++#include <boost/math/special_functions/bernoulli.hpp>
++#include <boost/multiprecision/cpp_bin_float.hpp>
++#include "compile_test/test_compile_result.hpp"
++
++void compile_and_link_test()
++{
++   check_result<boost::multiprecision::cpp_bin_float_50>(boost::math::bernoulli_b2n<boost::multiprecision::cpp_bin_float_50>(4));
++}