Merge llvm-project release/18.x llvmorg-18.1.1-0-gdba2a75e9c7e
This updates llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and
openmp to llvm-project release/18.x llvmorg-18.1.1-0-gdba2a75e9c7e.
PR: 276104
MFC after: 1 month
(cherry picked from commit 4c2d3b022a1d543dbbff75a0c53e8d3d7242216d)