Fix ifunc detection.

2018-01-26  Martin Liska  <mliska@suse.cz>

	* lib/target-supports.exp: Return a value, otherwise -Wreturn-type
	warning is seen.

From-SVN: r257094

gcc/testsuite/ChangeLog

+2018-01-26  Martin Liska  <mliska@suse.cz>
+
+	* lib/target-supports.exp: Return a value, otherwise -Wreturn-type
+	warning is seen.
+
 2018-01-26  Will Schmidt  <will_schmidt@vnet.ibm.com>
 
 	* gcc.target/powerpc/fold-vec-neg-longlong.h:  New.

gcc/testsuite/lib/target-supports.exp

@@ -449,7 +449,7 @@ proc check_ifunc_available { } {
 	extern "C" {
 	#endif
 	typedef void F (void);
-	F* g (void) {}
+	F* g (void) { return 0; }
 	void f () __attribute__ ((ifunc ("g")));
 	#ifdef __cplusplus
 	}