Added a check for macOS 11 and newer to resolve a compile error:
*** Unexpected product version 11.2.

Added Internals::getcwd.
Fallback to the built-in getcwd to resolve compile errors on macOS:
Can't locate Errno.pm in @INC
/miniperl not found

Signed-off-by: Georgi Valkov <gvalkov@abv.bg>

The perl Configure file was matching GCC 10 against "1*" and treating it
as GCC 1, causing ABI breakage and segfaults.

Cherry-pick the upstream patch which fixes it to check against (e.g)
"1.*" instead, which will make it work for hundreds more GCC versions
to come.

https://github.com/Perl/perl5/commit/6bd6308fcea3541
 "Adapt Configure to GCC version 10"

Also includes the previous commit just adding GCC 8 and 9 to one case:
https://github.com/Perl/perl5/commit/ae195500577d707
 "Add gcc-8 and gcc-9 for FORTIFY_SOURCE"

Signed-off-by: Ken Wong <xinxijishuwyq@gmail.com>