[generators] Implement %GeneratorGetSourcePosition.

src/compiler/access-builder.h

Index: src/compiler/access-builder.h
diff --git a/src/compiler/access-builder.h b/src/compiler/access-builder.h
index 7412a1d36ca4abd8abcb099e32704fd958ed1546..834522531002347232952998e9baacf8eafe2bb7 100644
--- a/src/compiler/access-builder.h
+++ b/src/compiler/access-builder.h
@@ -58,8 +58,8 @@ class AccessBuilder final : public AllStatic {
   // Provides access to JSGeneratorObject::continuation() field.
   static FieldAccess ForJSGeneratorObjectContinuation();
 
-  // Provides access to JSGeneratorObject::input() field.
-  static FieldAccess ForJSGeneratorObjectInput();
+  // Provides access to JSGeneratorObject::input_or_debug_pos() field.
+  static FieldAccess ForJSGeneratorObjectInputOrDebugPos();
 
   // Provides access to JSGeneratorObject::operand_stack() field.
   static FieldAccess ForJSGeneratorObjectOperandStack();