Add local type inference logic for integer literals.

pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart

 // Copyright (c) 2017, 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 file.
 
 import 'package:kernel/ast.dart';
 
 import '../builder/ast_factory.dart';
 import 'kernel_shadow_ast.dart';
 
 /// Concrete implementation of [builder.AstFactory] for building a kernel AST.
@@ skipping 23 matching lines @@
 
   @override
   KernelReturnStatement returnStatement(Expression expression, int charOffset) {
     return new KernelReturnStatement(expression)..fileOffset = charOffset;
   }
 
   @override
   KernelVariableDeclaration variableDeclaration(String name,
       {DartType type,
       Expression initializer,
-      int charOffset,
+      int charOffset = TreeNode.noOffset,

[ahe, 2017/04/20 09:45:29]

Perhaps this should be a required parameter?

[Paul Berry, 2017/04/20 09:52:57]

I don't know--does it make sense for a variableDeclaration to always have a
charOffset?  It seems to me like it does, but there are two callers that don't
supply one (BodyBuilder.endFunctionName and BodyBuilder.pushNewLocalVariable),
so I'm not really sure what the story is there.

[ahe, 2017/04/20 11:38:24]

I think both of those are mistakes that would be caught by making this parameter
required :-)

+      int equalsCharOffset = TreeNode.noOffset,
       bool isFinal: false,
       bool isConst: false}) {
     return new KernelVariableDeclaration(name,
         type: type,
         initializer: initializer,
         isFinal: isFinal,
         isConst: isConst)
-      ..fileEqualsOffset = charOffset;
+      ..fileOffset = charOffset
+      ..fileEqualsOffset = equalsCharOffset;
   }
 }