MIPS: Added Android-specific version of cacheflush call.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9234059
Patch from Daniel Kalmar <kalmard@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10518 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/cpu-mips.cc

-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -64,15 +64,19 @@ void CPU::FlushICache(void* start, size_t size) {
   }
 
 #if !defined (USE_SIMULATOR)
+#if defined(ANDROID)
+  // Bionic cacheflush can typically run in userland, avoiding kernel call.
+  char *end = reinterpret_cast<char *>(start) + size;
+  cacheflush(
+    reinterpret_cast<intptr_t>(start), reinterpret_cast<intptr_t>(end), 0);
+#else  // ANDROID
   int res;
-
   // See http://www.linux-mips.org/wiki/Cacheflush_Syscall.
   res = syscall(__NR_cacheflush, start, size, ICACHE);
-
   if (res) {
     V8_Fatal(__FILE__, __LINE__, "Failed to flush the instruction cache");
   }
-
+#endif  // ANDROID
 #else  // USE_SIMULATOR.
   // Not generating mips instructions for C-code. This means that we are
   // building a mips emulator based target.  We should notify the simulator