Most of the cases were where a C++ file was being compiled with the C substitution.
There were a few cases of the opposite though.
LLDB seems to be the only real culprit in the LLVM codebase for these mismatches.
Rest of the LLVM presumably sticks at least language-specific options in the common substitutions
making the mistakes immediately apparent.
I found these by using Clang frontend configuration files containing language-specific options for
both C and C++ (e.g. `-std=c2y` and `-std=c++26`).
By moving them into a folder with a local lit config
requiring x86. All these tests use x86 target triples.
There are two tests that require target-x86_64 because
they run program files (instead of just needing the backend).
Those are moved to the x86 folder also but their REQUIRES are
unchanged.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D100193
