Rename KernelElementAdapter and element_adapter.dart to IrToElementMap and ir_map.dart

pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart

Index: pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
diff --git a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
index b61e31461bfd19677a8638936df09838e350e8bd..4a4a87cd489da1c265748eb43f3965ddba7d5dcc 100644
--- a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
+++ b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
@@ -17,7 +17,7 @@ import '../elements/entities.dart';
 import '../elements/modelx.dart';
 import '../js/js.dart' as js;
 import '../js_backend/js_backend.dart';
-import '../kernel/element_adapter.dart';
+import '../kernel/ir_element_map.dart';
 import '../kernel/kernel.dart';
 import '../native/native.dart' as native;
 import '../resolution/tree_elements.dart';
@@ -35,7 +35,7 @@ import 'types.dart';
 /// A helper class that abstracts all accesses of the AST from Kernel nodes.
 ///
 /// The goal is to remove all need for the AST from the Kernel SSA builder.
-class KernelAstAdapter extends KernelElementAdapterMixin {
+class KernelAstAdapter extends IrToElementMapMixin {
   final Kernel kernel;
   final JavaScriptBackend _backend;
   final Map<ir.Node, ast.Node> _nodeToAst;