[CIR][CIRGen][NFC] Consolidate RUN lines for builtin tests

[ghehg]

There is no change to testing functionality. This refacot let those files have the same Run options that is easier to maintain and extend.

[bcardosolopes]

Thanks for trying to improve things, but I don't think this is the direction to go:

• These existing builtins tests are actually nicely categorized for what they cover.
• Most all tests have been designed to contain both CIR and LLVM outputs, I've been asking that for at least 6 months - easier to read and figure out bits all in one place, I don't see a rationale on why this is better.
• If you want a generic place for builtins you could create a builtin.cpp file for that and add new ones there, or ones that don't seem to require their own file. Note that there's not a single rule on how to go about these.
• bultins-overflow.cpp could probably be renamed to builtin-overflow.cpp to make names more uniform across the board.

[bcardosolopes]

Note: if for some reason while unifying things you find out that some don't have LLVM lowering yet, you can workaround by passing a -DFLAG to the -emit-llvm run line and use ifdefs to exclude the specific testcases that aren't yet supported. More or less what's done in clang/test/CIR/CodeGen/three-way-comparison.cpp.

[ghehg]

Thanks for trying to improve things, but I don't think this is the direction to go:

• These existing builtins tests are actually nicely categorized for what they cover.
• Most all tests have been designed to contain both CIR and LLVM outputs, I've been asking that for at least 6 months - easier to read and figure out bits all in one place, I don't see a rationale on why this is better.
• If you want a generic place for builtins you could create a builtin.cpp file for that and add new ones there, or ones that don't seem to require their own file. Note that there's not a single rule on how to go about these.
• bultins-overflow.cpp could probably be renamed to builtin-overflow.cpp to make names more uniform across the board.

Just as note, Bruno and I talked, and we repurposed this PR.