Include ':' before constructor separators into AST with Fasta.

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

Index: pkg/analyzer/lib/src/fasta/ast_builder.dart
diff --git a/pkg/analyzer/lib/src/fasta/ast_builder.dart b/pkg/analyzer/lib/src/fasta/ast_builder.dart
index c4831bb1c3a15ddd302232a3ef83c43ec9709def..bf5eda73f50a9e0baf74d06d456a6887e1341eaa 100644
--- a/pkg/analyzer/lib/src/fasta/ast_builder.dart
+++ b/pkg/analyzer/lib/src/fasta/ast_builder.dart
@@ -406,6 +406,7 @@ class AstBuilder extends ScopeListener {
 
   void handleNoInitializers() {
     debugEvent("NoInitializers");
+    push(NullValue.ConstructorInitializerSeparator);
     push(NullValue.ConstructorInitializers);
   }
 
@@ -413,6 +414,8 @@ class AstBuilder extends ScopeListener {
     debugEvent("Initializers");
     List<Object> initializerObjects = popList(count) ?? const [];
 
+    push(beginToken);
+
     var initializers = <ConstructorInitializer>[];
     for (Object initializerObject in initializerObjects) {
       if (initializerObject is FunctionExpressionInvocation) {
@@ -1567,6 +1570,7 @@ class AstBuilder extends ScopeListener {
     debugEvent("Function");
     FunctionBody body = pop();
     pop(); // constructor initializers
+    pop(); // ":" before constructor initializers
     FormalParameterList parameters = pop();
     TypeParameterList typeParameters = pop();
     // TODO(scheglov) It is an error if "getOrSet" is not null.
@@ -1632,11 +1636,11 @@ class AstBuilder extends ScopeListener {
     FunctionBody body = pop();
     ConstructorName redirectedConstructor = null; // TODO(paulberry)
     List<ConstructorInitializer> initializers = pop() ?? const [];
-    Token separator = null; // TODO(paulberry)
+    Token separator = pop();
     FormalParameterList parameters = pop();
-    TypeParameterList typeParameters = pop(); // TODO(paulberry)
+    TypeParameterList typeParameters = pop();
     var name = pop();
-    TypeAnnotation returnType = pop(); // TODO(paulberry)
+    TypeAnnotation returnType = pop();
     _Modifiers modifiers = pop();
     List<Annotation> metadata = pop();
     Comment comment = pop();