Fix type propagation for and operator.

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

Index: pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
diff --git a/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart b/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
index 5511118ee603a6cf9148ffdf3f5150b14cfe79f6..c5cdc94635fe5760331445267d7670d70d465c24 100644
--- a/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
+++ b/pkg/compiler/lib/src/ssa/invoke_dynamic_specializers.dart
@@ -564,7 +564,8 @@ class BitAndSpecializer extends BinaryBitOpSpecializer {
     HInstruction left = instruction.inputs[1];
     HInstruction right = instruction.inputs[2];
     JavaScriptBackend backend = compiler.backend;
-    if (left.isUInt31(compiler) || right.isUInt31(compiler)) {
+    if (left.isPrimitiveOrNull(compiler) &&
+        (left.isUInt31(compiler) || right.isUInt31(compiler))) {
       return backend.uint31Type;
     }
     return super.computeTypeFromInputTypes(instruction, compiler);