Small cleanups in RegExp to avoid generating lots of code just because there is a try/catch in our …

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 72 matching lines @@
       if (node.inputs[i].instructionType != HType.UNKNOWN) {
         allUnknown = false;
         break;
       }
     }
     if (allUnknown) return HTypeList.ALL_UNKNOWN;
 
     HTypeList result = new HTypeList(node.inputs.length - 1);
     for (int i = 0; i < result.types.length; i++) {
       result.types[i] = node.inputs[i + 1].instructionType;
+      assert(!result.types[i].isConflicting());
     }
     return result;
   }
 
   factory HTypeList.fromDynamicInvocation(HInvokeDynamic node,
                                           Selector selector) {
     HTypeList result;
     int argumentsCount = node.inputs.length - 1;
     int startInvokeIndex = HInvoke.ARGUMENTS_OFFSET;
 
     if (node.isInterceptorCall) {
       argumentsCount--;
       startInvokeIndex++;
     }
 
     if (selector.namedArgumentCount > 0) {
       result =
           new HTypeList.withNamedArguments(
               argumentsCount, selector.namedArguments);
     } else {
       result = new HTypeList(argumentsCount);
     }
 
     for (int i = 0; i < result.types.length; i++) {
       result.types[i] = node.inputs[i + startInvokeIndex].instructionType;
+      assert(!result.types[i].isConflicting());
     }
     return result;
   }
 
   static const HTypeList ALL_UNKNOWN = const HTypeList.withAllUnknown();
 
   bool get allUnknown => types == null;
   bool get hasNamedArguments => namedArguments != null;
   int get length => types.length;
   HType operator[](int index) => types[index];
@@ skipping 141 matching lines @@
   int constructorCount(Element element) {
     assert(element.isClass());
     Set<Element> ctors = constructors[element];
     return ctors == null ? 0 : ctors.length;
   }
 
   void registerFieldType(Map<Element, HType> typeMap,
                          Element field,
                          HType type) {
     assert(field.isField());
+    assert(!type.isConflicting());
     HType before = optimisticFieldType(field);
 
     HType oldType = typeMap[field];
     HType newType;
 
     if (oldType != null) {
       newType = oldType.union(type, compiler);
     } else {
       newType = type;
     }
@@ skipping 1207 matching lines @@
    *
    * Invariant: [element] must be a declaration element.
    */
   void eagerRecompile(Element element) {
     assert(invariant(element, element.isDeclaration));
     generatedCode.remove(element);
     generatedBailoutCode.remove(element);
     compiler.enqueuer.codegen.addToWorkList(element);
   }
 }