Infer types of bool/null/string literals.

pkg/front_end/lib/src/fasta/builder/ast_factory.dart

Index: pkg/front_end/lib/src/fasta/builder/ast_factory.dart
diff --git a/pkg/front_end/lib/src/fasta/builder/ast_factory.dart b/pkg/front_end/lib/src/fasta/builder/ast_factory.dart
index 52d2a08d538bb04657d9e17957d76183226013ff..09faabcc0c8e8cb4ef80a1c2e0eb00fef5da7479 100644
--- a/pkg/front_end/lib/src/fasta/builder/ast_factory.dart
+++ b/pkg/front_end/lib/src/fasta/builder/ast_factory.dart
@@ -38,6 +38,9 @@ abstract class AstFactory<V> {
   /// Creates a statement block.
   Block block(List<Statement> statements, Token beginToken);
 
+  /// Creates a boolean literal.
+  BoolLiteral boolLiteral(bool value, Token token);
+
   /// Creates a double literal.
   DoubleLiteral doubleLiteral(double value, Token token);
 
@@ -74,6 +77,13 @@ abstract class AstFactory<V> {
   /// Creates a read of a static variable.
   StaticGet staticGet(Member readTarget, Token token);
 
+  /// Creates a string concatenation.
+  StringConcatenation stringConcatenation(
+      List<Expression> expressions, Token token);
+
+  /// Creates a string literal.
+  StringLiteral stringLiteral(String value, Token token);
+
   /// Creates a variable declaration statement declaring one variable.
   ///
   /// TODO(paulberry): analyzer makes a distinction between a single variable