Handle the 'integer' values INFINITY and -INIFINITY in range analysis.

pkg/compiler/lib/src/ssa/value_range_analyzer.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 ssa;
 
 
 class ValueRangeInfo {
   final ConstantSystem constantSystem;
 
@@ skipping 665 matching lines @@
   Range visitConstant(HConstant hConstant) {
     if (!hConstant.isInteger(compiler)) return info.newUnboundRange();
     ConstantValue constant = hConstant.constant;
     NumConstantValue constantNum;
     if (constant is DeferredConstantValue) {
       constantNum = constant.referenced;
     } else {
       constantNum = constant;
     }
     if (constantNum.isMinusZero) constantNum = new IntConstantValue(0);
+    if (constantNum.isPositiveInfinity || constantNum.isNegativeInfinity) {
+      return info.newUnboundRange();
+    }
     Value value = info.newIntValue(constantNum.primitiveValue);
     return info.newNormalizedRange(value, value);
   }
 
   Range visitFieldGet(HFieldGet fieldGet) {
     if (!fieldGet.isInteger(compiler)) return info.newUnboundRange();
     if (!fieldGet.receiver.isIndexablePrimitive(compiler)) {
       return visitInstruction(fieldGet);
     }
     JavaScriptBackend backend = compiler.backend;
@@ skipping 379 matching lines @@
   }
 
   Range handleBinaryOperation(HBinaryArithmetic instruction) {
     Range leftRange = visit(instruction.left);
     Range rightRange = visit(instruction.right);
     if (leftRange == null || rightRange == null) return null;
     BinaryOperation operation = instruction.operation(info.constantSystem);
     return operation.apply(leftRange, rightRange);
   }
 }