Move sloppy block function hoisting logic from Parser to Scope.

src/ast/variables.h

Index: src/ast/variables.h
diff --git a/src/ast/variables.h b/src/ast/variables.h
index b56fb5b3483bb94bf758a41360ee148788e38ec0..460bb3801253e59f364102337cf283755fbb2d22 100644
--- a/src/ast/variables.h
+++ b/src/ast/variables.h
@@ -121,6 +121,11 @@ class Variable final : public ZoneObject {
     index_ = index;
   }
 
+  static InitializationFlag DefaultInitializationFlag(VariableMode mode) {
+    DCHECK(IsDeclaredVariableMode(mode));
+    return mode == VAR ? kCreatedInitialized : kNeedsInitialization;
+  }
+
  private:
   Scope* scope_;
   const AstRawString* name_;