Merge llvm-project main llvmorg-18-init-15088-gd14ee76181fb
This updates llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and
openmp to llvm-project main llvmorg-18-init-15088-gd14ee76181fb.
PR: 276104
MFC after: 1 month
(cherry picked from commit 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)