Fix setting $~ for Enumerator::Lazy#grep_v

Author: eregon

spec/tags/core/enumerator/lazy/grep_v_tags.txt

@@ -408,20 +408,18 @@ def grep(pattern, &block)
       end
     end
 
-    def grep_v(pattern)
-      if block_given?
-        Lazy.new(self, nil) do |yielder, *args|
-          val = args.length >= 2 ? args : args.first
-          unless pattern === val
-            # Regexp.set_block_last_match # TODO BJF Aug 2, 2016 Investigate for removal
+    def grep_v(pattern, &block)
+      binding = block ? block.binding : Truffle.invoke_primitive(:caller_binding)
+
+      Lazy.new(self, nil) do |yielder, *args|
+        val = args.length >= 2 ? args : args.first
+        matches = pattern === val
+        Truffle::RegexpOperations.set_last_match($~, binding)
+
+        unless matches
+          if block
             yielder.yield yield(val)
-          end
-        end
-      else
-        Lazy.new(self, nil) do |yielder, *args|
-          val = args.length >= 2 ? args : args.first
-          unless pattern === val
-            # Regexp.set_block_last_match # TODO BJF Aug 2, 2016 Investigate for removal
+          else
             yielder.yield val
           end
         end