Replace ${name} with $name where possible.

pkg/analyzer/test/generated/compile_time_error_code_test.dart

 // Copyright (c) 2014, 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.
 
 library engine.compile_time_error_code_test;
 
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 4637 matching lines @@
     Source source = addSource(r'''
 class A {
   set x(a, b) {}
 }''');
     resolve(source);
     assertErrors(source, [CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER]);
     verify([source]);
   }
 
   void _check_constEvalThrowsException_binary_null(String expr, bool resolved) {
-    Source source = addSource("const C = ${expr};");
+    Source source = addSource("const C = $expr;");
     resolve(source);
     if (resolved) {
       assertErrors(source, [CompileTimeErrorCode.CONST_EVAL_THROWS_EXCEPTION]);
       verify([source]);
     } else {
       assertErrors(source, [CompileTimeErrorCode.CONST_EVAL_THROWS_EXCEPTION]);
       // no verify(), 'null x' is not resolved
     }
     reset();
   }
@@ skipping 54 matching lines @@
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "");
     _check_wrongNumberOfParametersForOperator(name, "a, b");
   }
 }
 
 main() {
   _ut.groupSep = ' | ';
   runReflectiveTests(CompileTimeErrorCodeTest);
 }