Use the entity model for dump_info.

pkg/compiler/lib/src/universe/codegen_world_builder.dart

Index: pkg/compiler/lib/src/universe/codegen_world_builder.dart
diff --git a/pkg/compiler/lib/src/universe/codegen_world_builder.dart b/pkg/compiler/lib/src/universe/codegen_world_builder.dart
index 6cbe723b0500fd1ecc53fb465133694985ad4cc6..29e5195f77c828891fd166b20dbbde7b218504cf 100644
--- a/pkg/compiler/lib/src/universe/codegen_world_builder.dart
+++ b/pkg/compiler/lib/src/universe/codegen_world_builder.dart
@@ -18,6 +18,10 @@ abstract class CodegenWorldBuilder implements WorldBuilder {
   void forEachParameter(covariant FunctionEntity function,
       void f(DartType type, String name, ConstantValue defaultValue));
 
+  /// Calls [f] for each parameter - given as a [Local] - of [function].
+  void forEachParameterAsLocal(
+      covariant FunctionEntity function, void f(Local parameter));
+
   void forEachInvokedName(
       f(String name, Map<Selector, SelectorConstraints> selectors));
 
@@ -584,6 +588,8 @@ class ElementCodegenWorldBuilderImpl extends CodegenWorldBuilderImpl {
   @override
   void forEachParameter(MethodElement function,
       void f(DartType type, String name, ConstantValue defaultValue)) {
+    if (!function.hasFunctionSignature) return;
+    function = function.implementation;
     FunctionSignature parameters = function.functionSignature;
     parameters.orderedForEachParameter((_parameter) {
       ParameterElement parameter = _parameter;
@@ -595,6 +601,18 @@ class ElementCodegenWorldBuilderImpl extends CodegenWorldBuilderImpl {
     });
   }
 
+  @override
+  void forEachParameterAsLocal(
+      MethodElement function, void f(Local parameter)) {
+    if (!function.hasFunctionSignature) return;
+    function = function.implementation;
+    FunctionSignature parameters = function.functionSignature;
+    parameters.orderedForEachParameter((_parameter) {
+      ParameterElement parameter = _parameter;
+      f(parameter);
+    });
+  }
+
   @override
   void _processInstantiatedClassMember(
       ClassEntity cls, MemberElement member, MemberUsedCallback memberUsed) {
@@ -654,6 +672,13 @@ class KernelCodegenWorldBuilder extends CodegenWorldBuilderImpl {
     _elementMap.forEachParameter(function, f);
   }
 
+  @override
+  void forEachParameterAsLocal(
+      FunctionEntity function, void f(Local parameter)) {
+    throw new UnimplementedError(

[Siggi Cherem (dart-lang), 2017/08/30 17:30:42]

Johnni - how do you suggest we implement this. Do we want the _elementMap to
have access to the KernelToLocalsMap? Or should we undo some of the abstractions
here and let dump-info directly find the corresponding local?

+        'KernelCodegenWorldBuilder.forEachParameterAsLocal');
+  }
+
   @override
   void forEachInstanceField(
       ClassEntity cls, void f(ClassEntity declarer, FieldEntity field)) {