Fix issues due to updated toolchain.

Test: mma -j64 showcommands > make_log in platform/art. Also able to
produce abi dumps using header-abi-dumper.

Bug: 35845221

Change-Id: I569a1abff8df86da65af869b1c766ddeebf59ff4
diff --git a/runtime/class_table.cc b/runtime/class_table.cc
index af4f998..7c3ad12 100644
--- a/runtime/class_table.cc
+++ b/runtime/class_table.cc
@@ -55,6 +55,12 @@
   return nullptr;
 }
 
+// To take into account http://b/35845221
+#pragma clang diagnostic push
+#if __clang_major__ < 4
+#pragma clang diagnostic ignored "-Wunreachable-code"
+#endif
+
 mirror::Class* ClassTable::UpdateClass(const char* descriptor, mirror::Class* klass, size_t hash) {
   WriterMutexLock mu(Thread::Current(), lock_);
   // Should only be updating latest table.
@@ -80,6 +86,8 @@
   return existing;
 }
 
+#pragma clang diagnostic pop
+
 size_t ClassTable::CountDefiningLoaderClasses(ObjPtr<mirror::ClassLoader> defining_loader,
                                               const ClassSet& set) const {
   size_t count = 0;