Remove any unnecessary parens around expressions in interpolations.

pkg/analyzer/test/generated/resolver_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.resolver_test;
 
 import 'dart:collection';
 import 'package:analyzer/src/generated/java_core.dart';
 import 'package:analyzer/src/generated/java_junit.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
@@ skipping 6388 matching lines @@
   CompilationUnit resolveSource(String sourceText) => resolveSource2("/test.dart", sourceText);
 
   CompilationUnit resolveSource2(String fileName, String sourceText) {
     Source source = addNamedSource(fileName, sourceText);
     LibraryElement library = analysisContext.computeLibraryElement(source);
     return analysisContext.resolveCompilationUnit(source, library);
   }
 
   Source resolveSources(List<String> sourceTexts) {
     for (int i = 0; i < sourceTexts.length; i++) {
-      CompilationUnit unit = resolveSource2("/lib${(i + 1)}.dart", sourceTexts[i]);
+      CompilationUnit unit = resolveSource2("/lib${i + 1}.dart", sourceTexts[i]);
       // reference the source if this is the last source
       if (i + 1 == sourceTexts.length) {
         return unit.element.source;
       }
     }
     return null;
   }
 
   void resolveWithAndWithoutExperimental(List<String> strSources, List<ErrorCode> codesWithoutExperimental, List<ErrorCode> codesWithExperimental) {
     // Setup analysis context as non-experimental
@@ skipping 5072 matching lines @@
   runReflectiveTests(TypeResolverVisitorTest);
   runReflectiveTests(CheckedModeCompileTimeErrorCodeTest);
   runReflectiveTests(ErrorResolverTest);
   runReflectiveTests(HintCodeTest);
   runReflectiveTests(MemberMapTest);
   runReflectiveTests(NonHintCodeTest);
   runReflectiveTests(SimpleResolverTest);
   runReflectiveTests(StrictModeTest);
   runReflectiveTests(TypePropagationTest);
 }