[arm] Drop SMMLS support.

test/unittests/base/bits-unittest.cc

 // 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.
 
 #include <limits>
 
 #include "src/base/bits.h"
 #include "src/base/macros.h"
 #include "testing/gtest-support.h"
 
@@ skipping 206 matching lines @@
 TEST(Bits, SignedMulHighAndAdd32) {
   TRACED_FORRANGE(int32_t, i, 1, 50) {
     EXPECT_EQ(i, SignedMulHighAndAdd32(0, 0, i));
     TRACED_FORRANGE(int32_t, j, 1, i) {
       EXPECT_EQ(i, SignedMulHighAndAdd32(j, j, i));
     }
     EXPECT_EQ(i + 1, SignedMulHighAndAdd32(1024 * 1024 * 1024, 4, i));
   }
 }
 
-
-TEST(Bits, SignedMulHighAndSub32) {
-  TRACED_FORRANGE(int32_t, i, 1, 50) {
-    EXPECT_EQ(i, SignedMulHighAndSub32(0, 0, i));
-    TRACED_FORRANGE(int32_t, j, 1, i) {
-      EXPECT_EQ(i, SignedMulHighAndSub32(j, j, i));
-    }
-    EXPECT_EQ(i - 1, SignedMulHighAndSub32(1024 * 1024 * 1024, 4, i));
-  }
-}
-
 }  // namespace bits
 }  // namespace base
 }  // namespace v8