Fix bootstrap with g++

From-SVN: r177148

gcc/ada/gcc-interface/misc.c

@@ -637,6 +637,10 @@ must_pass_by_ref (tree gnu_type)
 	      && TREE_CODE (TYPE_SIZE (gnu_type)) != INTEGER_CST));
 }
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* This function is called by the front-end to enumerate all the supported
    modes for the machine, as well as some predefined C types.  F is a function
    which is called back with the parameters as listed below, first a string,
@@ -755,6 +759,11 @@ enumerate_modes (void (*f) (const char *, int, int, int, int, int, int))
     }
 }
 
+#ifdef __cplusplus
+}
+#endif
+
+
 /* Return the size of the FP mode with precision PREC.  */
 
 int