[gcc r11-7293] libstdc++: Fix __thread_relax for non-gthreads non-x86 targets

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:9d449189ee4304ce4f250351c8aa393324421eef

commit r11-7293-g9d449189ee4304ce4f250351c8aa393324421eef
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Feb 19 09:54:04 2021 +0000

    libstdc++: Fix __thread_relax for non-gthreads non-x86 targets
    
    My recent change to the preprocessor conditions in __thread_relax() was
    supposed to also change the __gthread_yield() call to __thread_yield(),
    which has the right preprocessor checks. Instead I just removed the
    check for _GLIBCXX_USE_SCHED_YIELD which means the __gthread_yield()
    call will be ill-formed for non-gthreads targets, and targets without
    sched_yield(). This fixes it properly.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/atomic_wait.h (__thread_relax()): Call
            __thread_yield() not __gthread_yield().

Diff:
---
 libstdc++-v3/include/bits/atomic_wait.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/bits/atomic_wait.h b/libstdc++-v3/include/bits/atomic_wait.h
index 37085ae8e50..424fccbe4c5 100644
--- a/libstdc++-v3/include/bits/atomic_wait.h
+++ b/libstdc++-v3/include/bits/atomic_wait.h
@@ -217,7 +217,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     __thread_yield() noexcept
     {
 #if defined _GLIBCXX_HAS_GTHREADS && defined _GLIBCXX_USE_SCHED_YIELD
-     __gthread_yield();
+      __gthread_yield();
 #endif
     }
 
@@ -227,7 +227,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #if defined __i386__ || defined __x86_64__
       __builtin_ia32_pause();
 #else
-      __gthread_yield();
+      __thread_yield();
 #endif
     }
   } // namespace __detail