[llvm] Reland "[LTO] Run Argument Promotion before IPSCCP" (PR #111853)

[Thurston Dang via llvm-commits]

thurstond wrote:

An msan buildbot (https://lab.llvm.org/buildbot/#/builders/164/builds/4320) started breaking around the time of this change; this change or https://github.com/llvm/llvm-project/pull/114964 are the only non-revert non-MLIR changes. Could you please take a look?

```
stage2/msan check

FAIL: Clang :: CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp (2331 of 86924)
******************** TEST 'Clang :: CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp' FAILED ********************
Exit Code: 1
Command Output (stderr):
--
RUN: at line 1: /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm_build_msan/bin/clang -cc1 -internal-isystem /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm_build_msan/lib/clang/20/include -nostdsysteminc -std=c++20 -fsyntax-only -verify /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp
+ /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm_build_msan/bin/clang -cc1 -internal-isystem /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm_build_msan/lib/clang/20/include -nostdsysteminc -std=c++20 -fsyntax-only -verify /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp
error: 'expected-error' diagnostics seen but not expected: 
  File /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp Line 73: static assertion failed due to requirement 'A<int>::B<int &>::y == 4'
  File /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp Line 77: static assertion failed due to requirement 'A<int>::x<int &> == 4'
error: 'expected-note' diagnostics seen but not expected: 
  File /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp Line 73: expression evaluates to '3 == 4'
  File /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/test/CXX/temp/temp.decls/temp.spec.partial/temp.spec.partial.member/p2.cpp Line 77: expression evaluates to '3 == 4'
```


https://github.com/llvm/llvm-project/pull/111853