Fix issues due to updated toolchain.

Supress -Winstantiation-after-specialization for clang_major >= 4.

Test: mma -j64.

Change-Id: I644c900999b07d62b7e13ef8c551f7af6f26ea48
diff --git a/runtime/base/arena_allocator.cc b/runtime/base/arena_allocator.cc
index 9fdb0cc..db43319 100644
--- a/runtime/base/arena_allocator.cc
+++ b/runtime/base/arena_allocator.cc
@@ -146,7 +146,9 @@
 }
 
 #pragma GCC diagnostic push
+#if __clang_major__ >= 4
 #pragma GCC diagnostic ignored "-Winstantiation-after-specialization"
+#endif
 // Explicitly instantiate the used implementation.
 template class ArenaAllocatorStatsImpl<kArenaAllocatorCountAllocations>;
 #pragma GCC diagnostic pop