in reply to
Can't compile XS code
undefined reference to `_imp__Perl_get_context'
I would think that symbol (and all of the others mentioned) should have been resolved by C:\strawberry\perl\lib\CORE\libperl516.a, to which you are apparently linking.
Run objdump -t C:\strawberry\perl\lib\CORE\libperl516.a >dump.txt and check that `_imp__Perl_get_context' can be found in the output that was sent to dump.txt.
Looking at my build of Strawberry 5.12, it looks like those symbols might be prefixed by 2 (not one) underscores. However, I don't know if such a discrepancy would matter anyway.
What does perl -V output. This is strange ... it shouldn't be happening.
Perhaps simply re-installing Strawberry Perl might fix the problem.