[turbofan] Fix more -Wsign-compare warnings.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 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.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 645 matching lines @@
   CheckPageFlag(js_function, scratch,
                 MemoryChunk::kPointersFromHereAreInterestingMask, eq, &done);
 
   const Register dst = scratch;
   add(dst, js_function, Operand(offset - kHeapObjectTag));
 
   push(code_entry);
 
   // Save caller-saved registers, which includes js_function.
   DCHECK((kCallerSaved & js_function.bit()) != 0);
-  DCHECK_EQ(kCallerSaved & code_entry.bit(), 0);
+  DCHECK_EQ(kCallerSaved & code_entry.bit(), 0u);
   stm(db_w, sp, (kCallerSaved | lr.bit()));
 
   int argument_count = 3;
   PrepareCallCFunction(argument_count, code_entry);
 
   mov(r0, js_function);
   mov(r1, dst);
   mov(r2, Operand(ExternalReference::isolate_address(isolate())));
 
   {
@@ skipping 3317 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM