mkoffload.c (process): Add C++ protection to emitted code.

	* config/nvptx/mkoffload.c (process): Add C++ protection to
	emitted code.

From-SVN: r225844

gcc/ChangeLog

+2015-07-15  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* config/nvptx/mkoffload.c (process): Add C++ protection to
+	emitted code.
+
 2015-07-14  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	PR target/66854

gcc/config/nvptx/mkoffload.c

@@ -867,7 +867,13 @@ process (FILE *in, FILE *out)
 		"func_mappings\n", nvars, nfuncs);
   fprintf (out, "};\n\n");
 
-  fprintf (out, "extern void GOMP_offload_register (const void *, int, void *);\n");
+  fprintf (out, "#ifdef __cplusplus\n"
+	   "extern \"C\" {\n"
+	   "#endif\n");
+  fprintf (out, "extern void GOMP_offload_register (void *, int, void *);\n");
+  fprintf (out, "#ifdef __cplusplus\n"
+	   "}\n"
+	   "#endif\n");
 
   fprintf (out, "extern void *__OFFLOAD_TABLE__[];\n\n");
   fprintf (out, "static __attribute__((constructor)) void init (void)\n{\n");