Don't recreate CoreTypes in transformers. Pass it in.

pkg/kernel/lib/transformations/reify/reify_transformer.dart

Index: pkg/kernel/lib/transformations/reify/reify_transformer.dart
diff --git a/pkg/kernel/lib/transformations/reify/reify_transformer.dart b/pkg/kernel/lib/transformations/reify/reify_transformer.dart
index 8a40128831dcdfd9df560b9aa609db77743b86d2..c015cb6e92cff5d2375ab0fb225a78cda3f740a0 100644
--- a/pkg/kernel/lib/transformations/reify/reify_transformer.dart
+++ b/pkg/kernel/lib/transformations/reify/reify_transformer.dart
@@ -41,15 +41,15 @@ RuntimeLibrary findRuntimeTypeLibrary(Program p) {
 }
 
 Program transformProgramUsingLibraries(
-    Program program, RuntimeLibrary runtimeLibrary,
+    CoreTypes coreTypes, Program program, RuntimeLibrary runtimeLibrary,
     [Library libraryToTransform]) {
   LibraryFilter filter = libraryToTransform != null
       ? (Library library) => library == libraryToTransform
       : (_) => true;
   ProgramKnowledge knowledge = analyze(program, analyzeLibrary: filter);
   Library mainLibrary = program.mainMethod.parent;
-  RuntimeTypeSupportBuilder builder = new RuntimeTypeSupportBuilder(
-      runtimeLibrary, new CoreTypes(program), mainLibrary);
+  RuntimeTypeSupportBuilder builder =
+      new RuntimeTypeSupportBuilder(runtimeLibrary, coreTypes, mainLibrary);
   ReifyVisitor transformer =
       new ReifyVisitor(runtimeLibrary, builder, knowledge, libraryToTransform);
   // Transform the main program.
@@ -66,10 +66,11 @@ Program transformProgramUsingLibraries(
   return program;
 }
 
-Program transformProgram(Program program) {
+Program transformProgram(CoreTypes coreTypes, Program program) {
   RuntimeLibrary runtimeLibrary = findRuntimeTypeLibrary(program);
   Library mainLibrary = program.mainMethod.enclosingLibrary;
-  return transformProgramUsingLibraries(program, runtimeLibrary, mainLibrary);
+  return transformProgramUsingLibraries(
+      coreTypes, program, runtimeLibrary, mainLibrary);
 }
 
 main(List<String> arguments) async {
@@ -80,11 +81,12 @@ main(List<String> arguments) async {
   }
   Uri uri = Uri.base.resolve(path);
   Program program = loadProgramFromBinary(uri.toFilePath());
+  CoreTypes coreTypes = new CoreTypes(program);
 
   RuntimeLibrary runtimeLibrary = findRuntimeTypeLibrary(program);
   Library mainLibrary = program.mainMethod.enclosingLibrary;
-  program =
-      transformProgramUsingLibraries(program, runtimeLibrary, mainLibrary);
+  program = transformProgramUsingLibraries(
+      coreTypes, program, runtimeLibrary, mainLibrary);
 
   if (output == null) {
     // Print result