Use __constinit keyword in libstdc++ sources

	* src/c++17/memory_resource.cc: Use __constinit keyword.

From-SVN: r275315

libstdc++-v3/ChangeLog

 2019-09-02  Jonathan Wakely  <jwakely@redhat.com>
 
+	* src/c++17/memory_resource.cc: Use __constinit keyword.
+
+2019-09-02  Jonathan Wakely  <jwakely@redhat.com>
+
 	* doc/xml/manual/abi.xml: Document 9.x library versions.
 	* doc/html/*: Regenerate.
 

libstdc++-v3/src/c++17/memory_resource.cc

@@ -85,8 +85,8 @@ namespace pmr
 	~constant_init() { /* do nothing, union member is not destroyed */ }
       };
 
-    constant_init<newdel_res_t> newdel_res{};
-    constant_init<null_res_t> null_res{};
+    __constinit constant_init<newdel_res_t> newdel_res{};
+    __constinit constant_init<null_res_t> null_res{};
 #if ATOMIC_POINTER_LOCK_FREE == 2
     using atomic_mem_res = atomic<memory_resource*>;
 # define _GLIBCXX_ATOMIC_MEM_RES_CAN_BE_CONSTANT_INITIALIZED
@@ -139,7 +139,7 @@ namespace pmr
 #endif // ATOMIC_POINTER_LOCK_FREE == 2
 
 #ifdef _GLIBCXX_ATOMIC_MEM_RES_CAN_BE_CONSTANT_INITIALIZED
-    constant_init<atomic_mem_res> default_res{&newdel_res.obj};
+    __constinit constant_init<atomic_mem_res> default_res{&newdel_res.obj};
 #else
 # include "default_resource.h"
 #endif