remove harmful declaration.

* variable.c (gen_ivtbl_get): declaration conflict on VC++.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57667 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

variable.c

@@ -976,7 +976,6 @@ gen_ivtbl_get(VALUE obj, struct gen_ivtbl **ivtbl)
 }
 
 /* for backwards compatibility only */
-NORETURN(st_table *rb_generic_ivar_table(VALUE));
 st_table*
 rb_generic_ivar_table(VALUE obj)
 {