Integrate LLVM to llvm/llvm-project@9550cd76cade (#24623)

Clean integrate, no reverts carried over.

Signed-off-by: Ege Beysel <beyselege@gmail.com>

third_party/llvm-project

diff --git a/third_party/llvm-project b/third_party/llvm-project
index 1e08997..9550cd7 160000
--- a/third_party/llvm-project
+++ b/third_party/llvm-project
@@ -1 +1 @@
-Subproject commit 1e0899794dd432c6c3c7bbba6940e8640e6a201c
+Subproject commit 9550cd76cadea9f25a5c0bf3ee06e9f7ce5631ed