Implement line and column numbers.

pkg/kernel/lib/ast.dart

Index: pkg/kernel/lib/ast.dart
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index 2f3cb111d74337e809f435bacbdfa2000ae8f9db..2044970b5e553dea2f4c70a7123bb81d5356d01f 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -3609,7 +3609,7 @@ class Program extends TreeNode {
   Program([List<Library> libraries, Map<String, Source> uriToSource])
       : libraries = libraries ?? <Library>[],
         uriToSource = uriToSource ?? <String, Source>{} {
-    setParents(libraries, this);
+    setParents(this.libraries, this);
   }
 
   accept(TreeVisitor v) => v.visitProgram(this);