Merge llvm-project main llvmorg-18-init-16595-g7c00a5be5cde
This updates llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and
openmp to llvm-project main llvmorg-18-init-16595-g7c00a5be5cde.
PR: 276104
MFC after: 1 month
(cherry picked from commit 1db9f3b21e39176dd5b67cf8ac378633b172463e)