Minor tweaks to the bitops builtin checks.

lib/compiler/implementation/ssa/nodes.dart

Index: lib/compiler/implementation/ssa/nodes.dart
diff --git a/lib/compiler/implementation/ssa/nodes.dart b/lib/compiler/implementation/ssa/nodes.dart
index 862556aa6983732ebbfa36de7b8263fd6c3e7aad..ba7eaf346de62395eb3a9238079700cede633aed 100644
--- a/lib/compiler/implementation/ssa/nodes.dart
+++ b/lib/compiler/implementation/ssa/nodes.dart
@@ -1381,7 +1381,7 @@ class HBinaryArithmetic extends HInvokeBinary {
   bool get builtin() => left.isNumber() && right.isNumber();
 
   HType computeTypeFromInputTypes() {
-    if (left.isInteger() && right.isInteger()) return left.propagatedType;
+    if (left.isInteger() && right.isInteger()) return HType.INTEGER;
     if (left.isNumber()) {
       if (left.isDouble() || right.isDouble()) return HType.DOUBLE;
       return HType.NUMBER;
@@ -1558,7 +1558,7 @@ class HShiftLeft extends HBinaryBitOp {
   // Shift left cannot be mapped to the native operator unless the
   // shift count is guaranteed to be an integer in the [0,31] range.
   bool get builtin() {
-    if (!left.isInteger() || !right.isConstantInteger()) return false;
+    if (!left.isNumber() || !right.isConstantInteger()) return false;
     HConstant rightConstant = right;
     IntConstant intConstant = rightConstant.constant;
     int count = intConstant.value;
@@ -1672,8 +1672,6 @@ class HBitNot extends HInvokeUnary {
   HBitNot(HStatic target, HInstruction input) : super(target, input);
   accept(HVisitor visitor) => visitor.visitBitNot(this);
 
-  bool get builtin() => operand.isInteger();
-
   HType computeTypeFromInputTypes() {
     // All bitwise operations on primitive types either produce an
     // integer or throw an error.