tcl: fix build on macos

configure script detects Darwin and uses flags incompatible with
Linux target build.

This patch uses fakeuname tool if host OS is MacOS to avoid Darwin
detection on target build.

Signed-off-by: Sergey V. Lobanov <sergey@lobanov.in>

lang/tcl/Makefile

@@ -23,6 +23,7 @@ PKG_LICENSE:=TCL
 PKG_LICENSE_FILES:=license.terms
 PKG_CPE_ID:=cpe:/a:tcl_tk:tcl_tk
 
+PKG_BUILD_DEPENDS:=HOST_OS_MACOS:fakeuname/host
 PKG_FIXUP:=autoreconf
 PKG_INSTALL:=1
 PKG_BUILD_PARALLEL:=1
@@ -31,6 +32,10 @@ HOST_BUILD_PARALLEL:=1
 include $(INCLUDE_DIR)/host-build.mk
 include $(INCLUDE_DIR)/package.mk
 
+ifeq ($(CONFIG_HOST_OS_MACOS),y)
+    include ../../utils/fakeuname/fakeuname.mk
+endif
+
 define Package/tcl
   SUBMENU:=Tcl
   SECTION:=lang
@@ -52,6 +57,7 @@ endef
 CONFIGURE_PATH := unix
 
 CONFIGURE_VARS += \
+	$(if $(CONFIG_HOST_OS_MACOS),PATH=$(FAKEUNAME_PATH):$(PATH)) \
 	tcl_cv_strtod_unbroken=ok
 
 CONFIGURE_ARGS += \