Add bool value types to type inference.

pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart

Index: pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
diff --git a/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart b/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
index efaae28d3b728f86ccb1c037e2e8c4a3bc2b79e6..1bcb5d59d18fb3cfc98893d06948d7678a756dc9 100644
--- a/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
+++ b/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
@@ -35,6 +35,7 @@ import '../resolution/tree_elements.dart' show
 import '../tree/tree.dart' as ast show
     DartString,
     Node,
+    LiteralBool,
     Send,
     SendSet,
     TryStatement;
@@ -242,6 +243,10 @@ class TypeInformationSystem extends TypeSystem<TypeInformation> {
         value, compiler.typesTask.stringType);
   }
 
+  TypeInformation boolLiteralType(ast.LiteralBool value) {
+    return new BoolLiteralTypeInformation(value, compiler.typesTask.boolType);

[sra1, 2015/09/29 01:02:04]

Is there a way to start tracking from a non-literal?
E.g.


    foo(const bool.fromEnvironment("DEBUG") == true);

[Harry Terkelsen, 2015/09/29 01:09:53]

Not yet, I want to add support for const bool expressions. Will add in upcoming
CL.

+  }
+
   TypeInformation computeLUB(TypeInformation firstType,
                              TypeInformation secondType) {
     if (firstType == null) return secondType;