Integrate LLVM at llvm/llvm-project@c56bbb3961e4

Updates LLVM usage to match
[c56bbb3961e4](https://github.com/llvm/llvm-project/commit/c56bbb3961e4)

PiperOrigin-RevId: 339442735
diff --git a/SUBMODULE_VERSIONS b/SUBMODULE_VERSIONS
index f05efbd..12a029a 100644
--- a/SUBMODULE_VERSIONS
+++ b/SUBMODULE_VERSIONS
@@ -6,7 +6,7 @@
 4fb0ff7069bd88ee85902f4d0bb62794e5f6d021 third_party/flatcc
 f2fb48c3b3d79a75a88a99fba6576b25d42ec528 third_party/googletest
 9f924ed7a8d476b22825fc3b98158e1d87c15085 third_party/llvm-bazel
-2e1a737f46460ddc15733f78acb42e27bc18a5ee third_party/llvm-project
+c56bbb3961e460cdff96c200068c073dd5d9f5cc third_party/llvm-project
 17b12a4481daa150e2d1ea3ada086b551b856707 third_party/marl
 d2cdb70e038370b5e28f353fe98ccd70af1cbc25 third_party/mlir-emitc
 d8c7ee00a687ac369e62e2032514a93a9b413502 third_party/pybind11