Add local type inference logic for integer literals.

pkg/front_end/lib/src/fasta/testing/suite.dart

 // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
 library fasta.testing.suite;
 
 import 'dart:async' show Future;
 
 import 'dart:convert' show JSON;
 
@@ skipping 174 matching lines @@
       ..input = Uri.parse("org.dartlang:platform") // Make up a name.
       ..setProgram(platform);
     KernelTarget sourceTarget = astKind == AstKind.Analyzer
         ? new AnalyzerTarget(dillTarget, context.uriTranslator, strongMode)
         : new KernelTarget(dillTarget, context.uriTranslator, strongMode);
 
     Program p;
     try {
       sourceTarget.read(description.uri);
       await dillTarget.writeOutline(null);
-      var instrumentation = new ValidatingInstrumentation();
-      await instrumentation.loadExpectations(description.uri);
-      sourceTarget.loader.instrumentation = instrumentation;
+      ValidatingInstrumentation instrumentation;
+      if (strongMode) {
+        instrumentation = new ValidatingInstrumentation();
+        await instrumentation.loadExpectations(description.uri);
+        sourceTarget.loader.instrumentation = instrumentation;
+      }
       p = await sourceTarget.writeOutline(null);
       if (fullCompile) {
         p = await sourceTarget.writeProgram(null);
-        instrumentation.finish();
-        if (instrumentation.hasProblems) {
+        instrumentation?.finish();
+        if (instrumentation != null && instrumentation.hasProblems) {
           if (updateExpectations) {
             await instrumentation.fixSource(description.uri);
           } else {
             return fail(null, instrumentation.problemsAsString);
           }
         }
       }
     } on InputError catch (e, s) {
       return fail(null, e.error, s);
     }
     return pass(p);
   }
 }