Revert "Force use of llvm libc implementation on mac os"

This reverts commit 5c11176cc0982a1c60744642db6e88fdfbb2e3b1.
Revert "include typedef of 'int32_t' for MSVS"

This reverts commit c3c8aae925fc72cb4ea3777eba3850129da86d30.
Use qint32 instead of int32_t. Oops!