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

pkg/compiler/lib/src/ssa/value_range_analyzer.dart

Index: pkg/compiler/lib/src/ssa/value_range_analyzer.dart
diff --git a/pkg/compiler/lib/src/ssa/value_range_analyzer.dart b/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
index a940e71fe72a1d90b07e514338536d981242b32c..9040670b3cc766457219e870e63dbac9ffc05b2f 100644
--- a/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
+++ b/pkg/compiler/lib/src/ssa/value_range_analyzer.dart
@@ -683,6 +683,9 @@ class SsaValueRangeAnalyzer extends HBaseVisitor implements OptimizationPhase {
       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);
   }