[gcc r13-5131] libstdc++: Do not include <system_error> in concurrency headers

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

https://gcc.gnu.org/g:227351345d0caa596eff8325144f15b15f704c08

commit r13-5131-g227351345d0caa596eff8325144f15b15f704c08
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Jan 12 13:03:01 2023 +0000

    libstdc++: Do not include <system_error> in concurrency headers
    
    The <condition_variable>, <mutex>, and <shared_mutex> headers use
    std::errc constants, but don't use std::system_error itself. They only
    use the __throw_system_error(int) function, which is defined in
    <bits/functexcept.h>.
    
    By including the header for the errc constants instead of the whole of
    <system_error> we avoid depending on the whole std::string definition.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/std_mutex.h: Remove <system_error> include.
            * include/std/condition_variable: Add <bits/error_constants.h>
            include.
            * include/std/mutex: Likewise.
            * include/std/shared_mutex: Likewise.

Diff:
---
 libstdc++-v3/include/bits/std_mutex.h       | 1 -
 libstdc++-v3/include/std/condition_variable | 3 ++-
 libstdc++-v3/include/std/mutex              | 2 +-
 libstdc++-v3/include/std/shared_mutex       | 1 +
 4 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/libstdc++-v3/include/bits/std_mutex.h b/libstdc++-v3/include/bits/std_mutex.h
index 68f5fb9ed65..bc515358d23 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -36,7 +36,6 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <system_error>
 #include <bits/functexcept.h>
 #include <bits/gthr.h>
 
diff --git a/libstdc++-v3/include/std/condition_variable b/libstdc++-v3/include/std/condition_variable
index b885e1baa1b..f671fe4afe1 100644
--- a/libstdc++-v3/include/std/condition_variable
+++ b/libstdc++-v3/include/std/condition_variable
@@ -38,6 +38,7 @@
 #else
 
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #include <bits/alloc_traits.h>
@@ -372,7 +373,7 @@ _GLIBCXX_BEGIN_INLINE_ABI_NAMESPACE(_V2)
         {
           return __p();
         }
- 
+
       std::stop_callback __cb(__stoken, [this] { notify_all(); });
       shared_ptr<mutex> __mutex = _M_mutex;
       while (!__p())
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index aca5f91e03c..4eedbe5038c 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -40,8 +40,8 @@
 #include <tuple>
 #include <exception>
 #include <type_traits>
-#include <system_error>
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #if ! _GTHREAD_USE_MUTEX_TIMEDLOCK
diff --git a/libstdc++-v3/include/std/shared_mutex b/libstdc++-v3/include/std/shared_mutex
index 7b70697f178..57c3cc54d81 100644
--- a/libstdc++-v3/include/std/shared_mutex
+++ b/libstdc++-v3/include/std/shared_mutex
@@ -36,6 +36,7 @@
 #if __cplusplus >= 201402L
 
 #include <bits/chrono.h>
+#include <bits/error_constants.h>
 #include <bits/functexcept.h>
 #include <bits/move.h>        // move, __exchange
 #include <bits/std_mutex.h>   // defer_lock_t