[clang] [Clang] [CodeGen] UBSan Trap Reasons (PR #145967)

[Anthony Tran via cfe-commits]

anthonyhatran wrote:

Anyways, to address Dan's comments, I changed all test cases so that they utilize `clang_cc1` instead of `clang`. This also meant that I had to change any `-fsanitize=undefined` and `-fsanitize-trap=undefined` to the specific check since `undefined` is a check grouping and is not recognized by front-end. I also adjusted the strings in the switch function to more closely match what was emitted when the test cases were run without `-fsanitize-trap=`, removed the unnecessary bug fix for unreachable, and added all test cases in for each `SanitizerHandler`, aside from `SanitizerHandler::BoundsSafety`.

https://github.com/llvm/llvm-project/pull/145967