openmp: BUILT_IN_GOMP_ENABLE_PINNED_MODE

Rework the GOMP_enable_pinned_mode call so that it works on powerpc where
the old way gave a local call.

gcc/ChangeLog:

	* omp-builtins.def (BUILT_IN_GOMP_ENABLE_PINNED_MODE): New.
	* omp-low.c (omp_enable_pinned_mode): Use
	BUILT_IN_GOMP_ENABLE_PINNED_MODE.

diff --git a/gcc/omp-builtins.def b/gcc/omp-builtins.def
index c591d79fa07..e442b0b5c94 100644
--- a/gcc/omp-builtins.def
+++ b/gcc/omp-builtins.def
@@ -468,3 +468,6 @@ DEF_GOMP_BUILTIN (BUILT_IN_GOMP_ERROR, "GOMP_error",
 DEF_GOMP_BUILTIN (BUILT_IN_GOMP_EVALUATE_TARGET_DEVICE, "GOMP_evaluate_target_device",
 		  BT_FN_BOOL_INT_CONST_PTR_CONST_PTR_CONST_PTR,
 		  ATTR_NOTHROW_LEAF_LIST)
+DEF_GOMP_BUILTIN (BUILT_IN_GOMP_ENABLE_PINNED_MODE,
+		  "GOMP_enable_pinned_mode",
+		  BT_FN_VOID, ATTR_NOTHROW_LIST)
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index f7ecfb52c73..4e8ab9e4ca0 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -15432,9 +15432,7 @@ omp_enable_pinned_mode ()
   push_struct_function (decl);
   init_tree_ssa (cfun);
 
-  tree callname = get_identifier ("GOMP_enable_pinned_mode");
-  tree calldecl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, callname,
-			      voidfntype);
+  tree calldecl = builtin_decl_explicit (BUILT_IN_GOMP_ENABLE_PINNED_MODE);
   gcall *call = gimple_build_call (calldecl, 0);
 
   gimple_seq seq = NULL;