ARM64: Fix SHR logic error.

test/mjsunit/compiler/shift-shr.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --noopt-safe-uint32-operations
+
+// Check the results of `left >>> right`. The result is always unsigned (and
+// therefore positive).
+function test_shr(left) {
+  var errors = 0;
+
+  for (var i = 1; i < 1024; i++) {
+    var temp = left >>> i;
+    if (temp < 0) {
+      errors++;
+    }
+  }
+
+  return errors;
+}
+
+assertEquals(0, test_shr(1));
+%OptimizeFunctionOnNextCall(test_shr);
+for (var i = 5; i >= -5; i--) {
+  assertEquals(0, test_shr(i));
+}