Fix following compiler warnings:

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 68 matching lines @@
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing VM code.
   __ movl(Address(CTX, Isolate::vm_tag_offset()), ECX);
 
   // Reserve space for arguments and align frame before entering C++ world.
-  __ AddImmediate(ESP, Immediate(-sizeof(NativeArguments)));
+  __ AddImmediate(ESP, Immediate(0 - sizeof(NativeArguments)));

[rmacnak, 2014/09/30 22:39:50]

I think these need a static_cast or there will be a warning about mixing signed
and unsigned values in arithmetic.

[siva, 2014/09/30 23:05:35]

Done.

   if (OS::ActivationFrameAlignment() > 1) {
     __ andl(ESP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call runtime.
   __ movl(Address(ESP, isolate_offset), CTX);  // Set isolate in NativeArgs.
   // There are no runtime calls to closures, so we do not need to set the tag
   // bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
   __ movl(Address(ESP, argc_tag_offset), EDX);  // Set argc in NativeArguments.
   __ leal(EAX, Address(EBP, EDX, TIMES_4, 1 * kWordSize));  // Compute argv.
@@ skipping 103 matching lines @@
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
   __ movl(Address(CTX, Isolate::vm_tag_offset()), ECX);
 
   // Reserve space for the native arguments structure, the outgoing parameters
   // (pointer to the native arguments structure, the C function entry point)
   // and align frame before entering the C++ world.
-  __ AddImmediate(ESP, Immediate(-sizeof(NativeArguments) - (2 * kWordSize)));
+  __ AddImmediate(ESP,
+                  Immediate(0 - sizeof(NativeArguments) - (2 * kWordSize)));
   if (OS::ActivationFrameAlignment() > 1) {
     __ andl(ESP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call native function.
   __ movl(Address(ESP, isolate_offset), CTX);  // Set isolate in NativeArgs.
   __ movl(Address(ESP, argc_tag_offset), EDX);  // Set argc in NativeArguments.
   __ movl(Address(ESP, argv_offset), EAX);  // Set argv in NativeArguments.
   __ leal(EAX, Address(EBP, 2 * kWordSize));  // Compute return value addr.
   __ movl(Address(ESP, retval_offset), EAX);  // Set retval in NativeArguments.
@@ skipping 83 matching lines @@
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
   __ movl(Address(CTX, Isolate::vm_tag_offset()), ECX);
 
   // Reserve space for the native arguments structure, the outgoing parameter
   // (pointer to the native arguments structure) and align frame before
   // entering the C++ world.
-  __ AddImmediate(ESP, Immediate(-sizeof(NativeArguments) - kWordSize));
+  __ AddImmediate(ESP, Immediate(0 - sizeof(NativeArguments) - kWordSize));
   if (OS::ActivationFrameAlignment() > 1) {
     __ andl(ESP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call native function.
   __ movl(Address(ESP, isolate_offset), CTX);  // Set isolate in NativeArgs.
   __ movl(Address(ESP, argc_tag_offset), EDX);  // Set argc in NativeArguments.
   __ movl(Address(ESP, argv_offset), EAX);  // Set argv in NativeArguments.
   __ leal(EAX, Address(EBP, 2 * kWordSize));  // Compute return value addr.
   __ movl(Address(ESP, retval_offset), EAX);  // Set retval in NativeArguments.
@@ skipping 1754 matching lines @@
   const Register temp = ECX;
   __ movl(left, Address(ESP, 2 * kWordSize));
   __ movl(right, Address(ESP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32