[clang] [llvm] [LLVM] Add IRNormalizer Pass (PR #68176)

[Vladimir Vereschaka via llvm-commits]

vvereschaka wrote:

Looks like these failed tests on [llvm-clang-x86_64-expensive-checks-ubuntu](https://lab.llvm.org/buildbot/#/builders/187) builder are related with this PR:
```
LLVM ERROR: Function @test changed by IRNormalizerPass without invalidating analyses
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/opt -S -passes=normalize
1.	Running pass "function(normalize)" on module "<stdin>"
2.	Running pass "normalize" on function "test"
 #0 0x00005643d9c9fdaa llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/lib/Support/Unix/Signals.inc:723:22
...
```
https://lab.llvm.org/buildbot/#/builders/187/builds/2031

https://github.com/llvm/llvm-project/pull/68176