Infer types of bool/null/string literals.

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

Index: pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
index ea9a35050a9a60c826a141a5bb98db8fa729a758..579afea6856d8d4afe147e6b0c288de655af7566 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_ast_factory.dart
@@ -18,6 +18,11 @@ class KernelAstFactory implements AstFactory<VariableDeclaration> {
   }
 
   @override
+  KernelBoolLiteral boolLiteral(bool value, Token token) {
+    return new KernelBoolLiteral(value)..fileOffset = offsetForToken(token);
+  }
+
+  @override
   KernelDoubleLiteral doubleLiteral(double value, Token token) {
     return new KernelDoubleLiteral(value)..fileOffset = offsetForToken(token);
   }
@@ -80,6 +85,18 @@ class KernelAstFactory implements AstFactory<VariableDeclaration> {
   }
 
   @override
+  StringConcatenation stringConcatenation(
+      List<Expression> expressions, Token token) {
+    return new KernelStringConcatenation(expressions)
+      ..fileOffset = offsetForToken(token);
+  }
+
+  @override
+  StringLiteral stringLiteral(String value, Token token) {
+    return new KernelStringLiteral(value)..fileOffset = offsetForToken(token);
+  }
+
+  @override
   VariableDeclaration variableDeclaration(
       String name, Token token, int functionNestingLevel,
       {DartType type,