Remove wrong assert: the guarded instruction could be generate at use site if it is a HCheck instru…

lib/compiler/implementation/ssa/codegen.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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
 
   String buildJavaScriptFunction(FunctionElement element,
@@ skipping 2240 matching lines @@
     } else {
       assert(guard.guarded is HParameterValue);
       buffer.add(' 0');
     }
     buffer.add(')');
   }
 
   void visitTypeGuard(HTypeGuard node) {
     addIndentation();
     HInstruction input = node.guarded;
-    assert(!isGenerateAtUseSite(input) || input.isCodeMotionInvariant());
     if (node.isInteger()) {
       buffer.add('if (');
       checkInt(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not an integer');
     } else if (node.isNumber()) {
       buffer.add('if (');
       checkNum(input, '!==');
       buffer.add(') ');
       bailout(node, 'Not a number');
@@ skipping 339 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endLabeledBlock(HLabeledBlockInformation labeledBlockInfo) {
     if (labeledBlockInfo.body.start.hasGuards()) {
       endBailoutSwitch();
     }
   }
 }