svn commit: r351253 - in head/contrib/libc++: include src

[Mark Millard]

> Author: dim
> Date: Tue Aug 20 17:39:32 2019
> New Revision: 351253
> URL: 
> https://svnweb.freebsd.org/changeset/base/351253
> 
> 
> Log:
>   Pull in r368867 from upstream libc++ trunk (by Marshall Clow):
>   
>     Rework recursive_timed_mutex so that it uses __thread_id instead of
>     using the lower-level __libcpp_thread_id. This is prep for fixing
>     PR42918. Reviewed as 
> https://reviews.llvm.org/D65895
> 
>   
>   Pull in r368916 from upstream libc++ trunk (by Marshall Clow):
>   
>     Fix thread comparison by making sure we never pass our special 'not a
>     thread' value to the underlying implementation. Fixes PR#42918.

FYI: llvm's -r368916 has a successor fix: -r329399 tied to:

https:://reviews.llvm.org/D66480

that is summarized with:

QUOTE
In fixing https://bugs.llvm.org/show_bug.cgi?id=42918 (r368916), I broke external threading support.
This should fix that
END QUOTE


===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)