dart2js: Constant folding and specialization for remainder

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

Index: pkg/compiler/lib/src/ssa/types_propagation.dart
diff --git a/pkg/compiler/lib/src/ssa/types_propagation.dart b/pkg/compiler/lib/src/ssa/types_propagation.dart
index 63da62838697773958f65cb1560c06e0625eb856..92abbbfc32952e1e2e1f555877cebe25c35c7510 100644
--- a/pkg/compiler/lib/src/ssa/types_propagation.dart
+++ b/pkg/compiler/lib/src/ssa/types_propagation.dart
@@ -143,6 +143,11 @@ class SsaTypePropagator extends HBaseVisitor implements OptimizationPhase {
     return instruction.instructionType;
   }
 
+  TypeMask visitRemainder(HRemainder instruction) {
+    // Always as initialized.
+    return instruction.instructionType;
+  }
+
   TypeMask visitNegate(HNegate instruction) {
     HInstruction operand = instruction.operand;
     // We have integer subclasses that represent ranges, so widen any int