vm_insnhelper.c: fix ALWAYS_INLINE usage

* vm_insnhelper.c (vm_getivar): ALWAYS_INLINE macro needs an
  argument.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55884 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm_insnhelper.c

@@ -861,7 +861,8 @@ vm_search_const_defined_class(const VALUE cbase, ID id)
 #define USE_IC_FOR_IVAR 1
 #endif
 
-ALWAYS_INLINE() inline VALUE
+ALWAYS_INLINE(static VALUE vm_getivar(VALUE, ID, IC, struct rb_call_cache *, int));
+static inline VALUE
 vm_getivar(VALUE obj, ID id, IC ic, struct rb_call_cache *cc, int is_attr)
 {
 #if USE_IC_FOR_IVAR