llvm-project

82cf54fb - [UTC] CHECK-EMPTY instead of skipping blank lines (#165718)

[UTC] CHECK-EMPTY instead of skipping blank lines (#165718) Previously, any blank lines in IR were ignored by UTC, leading to more fragile `CHECK`s being generated. This change lets UTC, 1) emit `CHECK-EMPTY` to check blank lines, and 2) generate more `CHECK-NEXT`s, landing the discussion https://github.com/llvm/llvm-project/pull/165419#issuecomment-3457572422. Moreover, this change also aligns the behavior of IR check-gen to ASM check-gen, which has been emitting `CHECK-EMPTY` since https://github.com/llvm/llvm-project/commit/a8a89c77ea3c16b45763fca6940bbfd3bef7884f.