llvm-project

b7d64384 - [libc] implement recursive mutex and fix wrong initializer (#193992)

[libc] implement recursive mutex and fix wrong initializer (#193992) Fix #193892. This is found during libc++ bringing up process. This patch: - implement recursive mutex support for real. - fix the issue that pthread mutex initializer and public mutex interface misalign with internal representation. this was the root cause that hangs the libc++ test as padding bytes effectively pollute the futex state if default initializer was used. - additionally, we changed the field to bitfield to allow encoding more data. (e.g. the error checking flag that is not yet added). timed bit is removed as we always support it anyway. PI bit is added instead.