Fix compilation with GCC 4.8

src/checks.h

Index: src/checks.h
diff --git a/src/checks.h b/src/checks.h
index 9d2db28d8f3106f1e781c2d69820089d7b82f0ad..a6df48e9147ff6ec5509b35cf9a04ee054e450dc 100644
--- a/src/checks.h
+++ b/src/checks.h
@@ -268,7 +268,8 @@ template <int> class StaticAssertionHelper { };
 #define STATIC_CHECK(test)                                                    \
   typedef                                                                     \
     StaticAssertionHelper<sizeof(StaticAssertion<static_cast<bool>((test))>)> \
-    SEMI_STATIC_JOIN(__StaticAssertTypedef__, __LINE__)
+    SEMI_STATIC_JOIN(__StaticAssertTypedef__, __LINE__)                       \
+    __attribute__((unused))  // Silence GCC-4.8's warnings.

[Benedikt Meurer, 2013/11/12 10:31:42]

This will fail on Visual Studio. Please add an appropriate define
V8_HAS_ATTRIBUTE_UNUSED to include/v8config.h (Clang requires an __has_attribute
test, whereas for GCC a version test is sufficient), and define a V8_UNUSED
macro based on that, similar to what we do with the other compiler specific
stuff.

[Jakob Kummerow, 2013/11/12 12:01:29]

Done.

 #endif