PCH: Add multi-language PCH generation support
If the target has C files, it will get a C PCH file. The same for C++ files. The linker language is no longer used to determine which language to use for PCH.
Fixes: #19790 (closed)
If the target has C files, it will get a C PCH file. The same for C++ files. The linker language is no longer used to determine which language to use for PCH.
Fixes: #19790 (closed)