MIPS: Fixing CLANG compilation warnings

src/mips64/cpu-mips64.cc

Index: src/mips64/cpu-mips64.cc
diff --git a/src/mips64/cpu-mips64.cc b/src/mips64/cpu-mips64.cc
index 6e5910b3ffc5e81b24ac437ac1f48bfee4580b48..ab9cf69620e3ebd315bdb649c9916deeb40d4b5b 100644
--- a/src/mips64/cpu-mips64.cc
+++ b/src/mips64/cpu-mips64.cc
@@ -35,7 +35,7 @@ void CpuFeatures::FlushICache(void* start, size_t size) {
   cacheflush(
     reinterpret_cast<intptr_t>(start), reinterpret_cast<intptr_t>(end), 0);
 #else  // ANDROID
-  int res;
+  long res;  // NOLINT(runtime/int)

[balazs.kilvady, 2015/12/02 18:49:07]

Do we need long at here? syscall returns with int.

[ivica.bogosavljevic, 2015/12/03 10:36:24]

On MIPS64, if we leave int here than we cannot compile it under CLANG. If we set
long, it compiles both under GCC and CLANG. I executed all the tests and I
didn't see any new failures or something suspicious. 

The specification is ambiguous, I read that syscall can return long (e.g.
http://man7.org/linux/man-pages/man2/syscall.2.html) or int (on my system man
syscall) 

   // See http://www.linux-mips.org/wiki/Cacheflush_Syscall.
   res = syscall(__NR_cacheflush, start, size, ICACHE);
   if (res) {