[gcc r13-5153] libstdc++: Add <errno.h> to <bits/std_mutex.h>

[Jonathan Wakely]

https://gcc.gnu.org/g:b4b1c6aa6d28d3afe989a6dc3210606a3d55a367

commit r13-5153-gb4b1c6aa6d28d3afe989a6dc3210606a3d55a367
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Jan 13 16:37:57 2023 +0000

    libstdc++: Add <errno.h> to <bits/std_mutex.h>
    
    This needs to be included explicitly now that we don't include all of
    <system_error> here.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/std_mutex.h: Include <errno.h>.

Diff:
---
 libstdc++-v3/include/bits/std_mutex.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libstdc++-v3/include/bits/std_mutex.h b/libstdc++-v3/include/bits/std_mutex.h
index bc515358d23..f74ddc4123a 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -36,6 +36,7 @@
 # include <bits/c++0x_warning.h>
 #else
 
+#include <errno.h> // EBUSY
 #include <bits/functexcept.h>
 #include <bits/gthr.h>