Reapply "[NFC][clang] Add ubsan-trap-merge.c test to show absence of nomerge" (#117804)#117805

thurstond merged 1 commit intollvm:mainllvm/llvm-project:mainfrom

thurstond:reland_ubsan_trap_merge_testthurstond/llvm-project:reland_ubsan_trap_merge_testCopy head branch name to clipboard