array.c: GC guard

* array.c (rb_ary_splice): prevent replacing array from GC.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47683 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

array.c

@@ -1606,6 +1606,7 @@ rb_ary_splice(VALUE ary, long beg, long len, VALUE rpl)
 	    MEMMOVE(RARRAY_PTR(ary) + beg, RARRAY_CONST_PTR(rpl), VALUE, rlen);
 	}
     }
+    RB_GC_GUARD(rpl);
 }
 
 void