[cfe] Fix crash on const constructor tear-off

Closes #46133.

Bug: https://github.com/dart-lang/sdk/issues/46133
Change-Id: I73035d2b27a2d8116fa7c31abdebfdd7299d6898
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/212572
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Dmitry Stefantsov <dmitryas@google.com>

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

@@ -4833,6 +4833,8 @@ class BodyBuilder extends ScopeListener<JumpTarget>
     } else if (type is ParserRecovery) {
       push(new ParserErrorGenerator(
           this, nameToken, fasta.messageSyntheticToken));
+    } else if (type is InvalidExpression) {
+      push(type);
     } else if (type is Expression) {
       push(createInstantiationAndInvocation(
           () => type, typeArguments, name, name, arguments,

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class A {}
+
+test() => A.const.toString();
+
+main() {}

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.expect

@@ -0,0 +1,28 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: Expected an identifier, but got '.'.
+// Try inserting an identifier before '.'.
+// test() => A.const.toString();
+//                  ^
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+// Try inserting an identifier before 'const'.
+// test() => A.const.toString();
+//             ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  synthetic constructor •() → self::A
+    : super core::Object::•()
+    ;
+}
+static method test() → dynamic
+  return invalid-expression "pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+Try inserting an identifier before 'const'.
+test() => A.const.toString();
+            ^^^^^";
+static method main() → dynamic {}

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.strong.transformed.expect

@@ -0,0 +1,28 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: Expected an identifier, but got '.'.
+// Try inserting an identifier before '.'.
+// test() => A.const.toString();
+//                  ^
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+// Try inserting an identifier before 'const'.
+// test() => A.const.toString();
+//             ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  synthetic constructor •() → self::A
+    : super core::Object::•()
+    ;
+}
+static method test() → dynamic
+  return invalid-expression "pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+Try inserting an identifier before 'const'.
+test() => A.const.toString();
+            ^^^^^";
+static method main() → dynamic {}

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.textual_outline.expect

@@ -0,0 +1,3 @@
+class A {}
+test() => A.const.toString();
+main() {}

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.weak.expect

@@ -0,0 +1,28 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: Expected an identifier, but got '.'.
+// Try inserting an identifier before '.'.
+// test() => A.const.toString();
+//                  ^
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+// Try inserting an identifier before 'const'.
+// test() => A.const.toString();
+//             ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  synthetic constructor •() → self::A
+    : super core::Object::•()
+    ;
+}
+static method test() → dynamic
+  return invalid-expression "pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+Try inserting an identifier before 'const'.
+test() => A.const.toString();
+            ^^^^^";
+static method main() → dynamic {}

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.weak.outline.expect

@@ -0,0 +1,20 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: Expected an identifier, but got '.'.
+// Try inserting an identifier before '.'.
+// test() => A.const.toString();
+//                  ^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  synthetic constructor •() → self::A
+    ;
+}
+static method test() → dynamic
+  ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/constructor_tearoffs/issue46133.dart.weak.transformed.expect

@@ -0,0 +1,28 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:18: Error: Expected an identifier, but got '.'.
+// Try inserting an identifier before '.'.
+// test() => A.const.toString();
+//                  ^
+//
+// pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+// Try inserting an identifier before 'const'.
+// test() => A.const.toString();
+//             ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+
+class A extends core::Object {
+  synthetic constructor •() → self::A
+    : super core::Object::•()
+    ;
+}
+static method test() → dynamic
+  return invalid-expression "pkg/front_end/testcases/constructor_tearoffs/issue46133.dart:7:13: Error: Expected an identifier, but got 'const'.
+Try inserting an identifier before 'const'.
+test() => A.const.toString();
+            ^^^^^";
+static method main() → dynamic {}

pkg/front_end/testcases/textual_outline.status

@@ -23,6 +23,7 @@ regress/utf_16_le_content.crash: EmptyOutput
 const_functions/const_functions_const_ctor: FormatterCrash
 const_functions/const_functions_const_ctor_error: FormatterCrash
 const_functions/const_functions_const_factory: FormatterCrash
+constructor_tearoffs/issue46133: FormatterCrash
 constructor_tearoffs/issue47075: FormatterCrash
 dart2js/late_fields: FormatterCrash
 dart2js/late_statics: FormatterCrash