Add AstBuilder support for TypeArguments.

R=scheglov@google.com

Review-Url: https://codereview.chromium.org/2716483002 .

pkg/analyzer/test/generated/parser_fasta_test.dart

@@ -464,7 +464,7 @@ class FormalParameterParserTest_Fasta extends FastaParserTestCase
   @override
   @failingTest
   void test_parseFormalParameter_covariant_type_normal() {
-    // TODO(scheglov): Unhandled event: TypeArguments
+    // TODO(paulberry): Covariant keyword is not yet supported.
     super.test_parseFormalParameter_covariant_type_normal();
   }
 
@@ -986,7 +986,7 @@ class TopLevelParserTest_Fasta extends FastaParserTestCase
   @override
   @failingTest
   void test_parseCompilationUnit_exportAsPrefix_parameterized() {
-    // TODO(paulberry): Unhandled event: TypeArguments
+    // TODO(paulberry): As of commit 5de9108 this syntax is invalid.
     super.test_parseCompilationUnit_exportAsPrefix_parameterized();
   }
 
@@ -1028,13 +1028,6 @@ class TopLevelParserTest_Fasta extends FastaParserTestCase
         .test_parseCompilationUnitMember_function_generic_noReturnType_annotated();
   }
 
-  @override
-  @failingTest
-  void test_parseCompilationUnitMember_typeAlias_generic() {
-    // TODO(paulberry): Unhandled event: TypeArguments
-    super.test_parseCompilationUnitMember_typeAlias_generic();
-  }
-
   void test_parseCompilationUnitMember_typedef() {
     // TODO(paulberry): Unhandled event: FunctionTypeAlias
     super.test_parseCompilationUnitMember_typedef();
@@ -1125,13 +1118,6 @@ class TopLevelParserTest_Fasta extends FastaParserTestCase
     super.test_parsePartOfDirective_uri();
   }
 
-  @override
-  @failingTest
-  void test_parseTypeAlias_function_parameterizedReturnType() {
-    // TODO(paulberry): Unhandled event: TypeArguments
-    super.test_parseTypeAlias_function_parameterizedReturnType();
-  }
-
   @override
   @failingTest
   void test_parseTypeAlias_genericFunction_noParameters() {

pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart

@@ -478,7 +478,8 @@ class AstBuilder extends ScopeListener {
     SimpleIdentifier name = pop();
     TypeName type = pop();
     Token keyword = _popOptionalSingleModifier();
-    pop(); // Metadata.
+    pop(); // TODO(paulberry): Metadata.
+    // TODO(paulberry): handle covariant keyword.
     SimpleFormalParameter node = ast.simpleFormalParameter(
         null, null, toAnalyzerToken(keyword), type, name);
     scope[name.name] = name.staticElement = new AnalyzerParameterElement(node);
@@ -1085,6 +1086,7 @@ class AstBuilder extends ScopeListener {
         toAnalyzerToken(endToken)));
   }
 
+  @override
   void endEnum(Token enumKeyword, Token endBrace, int count) {
     debugEvent("Enum");
     List<EnumConstantDeclaration> constants = popList(count);
@@ -1107,6 +1109,14 @@ class AstBuilder extends ScopeListener {
         toAnalyzerToken(closeBrace)));
   }
 
+  @override
+  void endTypeArguments(int count, Token beginToken, Token endToken) {
+    debugEvent("TypeArguments");
+    List<TypeAnnotation> arguments = popList(count);
+    push(ast.typeArgumentList(
+        toAnalyzerToken(beginToken), arguments, toAnalyzerToken(endToken)));
+  }
+
   /**
    * Pop the modifiers list, if the list is empty return `null`, if the list
    * has one item return it; otherwise return `null`.