Fix old-style function definitions and enable warning. (#1651)

Function definitions with no parameters should always use the void keyword to allow the compiler to catch invalid calls of those functions at compile time.

Enable -Wold-style-definition to catch this early in the future.

Fixes #1649.

JerryScript-DCO-1.0-Signed-off-by: Tilmann Scheller t.scheller@samsung.com

jerry-core/parser/regexp/re-compiler.c

@@ -488,7 +488,7 @@ re_find_bytecode_in_cache (ecma_string_t *pattern_str_p, /**< pattern string */
  * Run gerbage collection in RegExp cache
  */
 void
-re_cache_gc_run ()
+re_cache_gc_run (void)
 {
   for (uint32_t i = 0u; i < RE_CACHE_SIZE; i++)
   {