Close https://github.com/llvm/llvm-project/issues/75057
Previously, I thought the diagnostic mappings is not meaningful with
modules incorrectly. And this problem get revealed by another change
recently. So this patch tried to rever the previous "optimization"
partially.
and "[NFC] [C++20] [Modules] Use new class CXX20ModulesGenerator to
generate module file for C++20 modules instead of PCHGenerator"
This reverts commit fb21343473e33e9a886b42d2fe95d1cec1cd0030.
and commit 18268ac0f48d93c2bcddb69732761971669c09ab.
It looks like there are some problems about linking the compiler
Close https://github.com/llvm/llvm-project/issues/75057
Previously, I thought the diagnostic mappings is not meaningful with
modules incorrectly. And this problem get revealed by another change
recently. So this patch tried to rever the previous "optimization"
partially.
