[turbofan] Implement OSR for outer loops.

src/compiler/graph-builder.h

Index: src/compiler/graph-builder.h
diff --git a/src/compiler/graph-builder.h b/src/compiler/graph-builder.h
index 0fdd7692cc1a87a9b82a956384ab45b039308f7b..c708e64b644e789f0a675b7b3a12c7c63a89c453 100644
--- a/src/compiler/graph-builder.h
+++ b/src/compiler/graph-builder.h
@@ -218,8 +218,8 @@ class StructuredGraphBuilder::Environment : public ZoneObject {
   }
 
   // Copies this environment at a loop header control-flow point.
-  Environment* CopyForLoop(BitVector* assigned) {
-    PrepareForLoop(assigned);
+  Environment* CopyForLoop(BitVector* assigned, bool is_osr = false) {
+    PrepareForLoop(assigned, is_osr);
     return builder()->CopyEnvironment(this);
   }
 
@@ -233,7 +233,7 @@ class StructuredGraphBuilder::Environment : public ZoneObject {
   NodeVector* values() { return &values_; }
 
   // Prepare environment to be used as loop header.
-  void PrepareForLoop(BitVector* assigned);
+  void PrepareForLoop(BitVector* assigned, bool is_osr = false);
 
  private:
   StructuredGraphBuilder* builder_;