Remove V8_WARN_UNUSED_RESULT for simple getters.

src/cpu.h

Index: src/cpu.h
diff --git a/src/cpu.h b/src/cpu.h
index 58c7f5d9d4a8b8610eaca8c00e7c8866c3d99931..b2e9f7da7ee539581965f7e7991951ee420678b5 100644
--- a/src/cpu.h
+++ b/src/cpu.h
@@ -100,7 +100,7 @@ class CPU V8_FINAL BASE_EMBEDDED {
   bool has_vfp3_d32() const { return has_vfp3_d32_; }
 
   // Returns the number of processors online.
-  static int NumberOfProcessorsOnline() V8_WARN_UNUSED_RESULT;
+  static int NumberOfProcessorsOnline();
 
   // Initializes the cpu architecture support. Called once at VM startup.
   static void SetUp();