[committed] libstdc++: Add _Exit to for freestanding

[Jonathan Wakely via Gcc-patches]

Tested powerpc64le-linux, pushed to trunk.

-- >8 --

When I added std::_Exit to the freestanding declarations in <cstdlib> I
should also have added it to <stdlib.h>.

libstdc++-v3/ChangeLog:

        * include/c_compatibility/stdlib.h [!_GLIBCXX_HOSTED]: Add
        using-declaration for _Exit.
---
 libstdc++-v3/include/c_compatibility/stdlib.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libstdc++-v3/include/c_compatibility/stdlib.h 
b/libstdc++-v3/include/c_compatibility/stdlib.h
index 377b9107ded..70fa4c8e503 100644
--- a/libstdc++-v3/include/c_compatibility/stdlib.h
+++ b/libstdc++-v3/include/c_compatibility/stdlib.h
@@ -45,6 +45,9 @@ using std::exit;
 # ifdef _GLIBCXX_HAVE_QUICK_EXIT
   using std::quick_exit;
 # endif
+# if _GLIBCXX_USE_C99_STDLIB
+  using std::_Exit;
+# endif
 #endif
 
 #if _GLIBCXX_HOSTED
-- 
2.37.3