Protect __shared_weak_count::__get_deleter declaration with _LIBCPP_NO_RTTI.  Fixes http://llvm.org/bugs/show_bug.cgi?id=12867

llvm-svn: 157049
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 9042d623bf149afa70c16fb28f2b2095ab495c5d
diff --git a/include/memory b/include/memory
index e30a6fd..8456a94 100644
--- a/include/memory
+++ b/include/memory
@@ -3603,7 +3603,9 @@
     long use_count() const _NOEXCEPT {return __shared_count::use_count();}
     __shared_weak_count* lock() _NOEXCEPT;
 
+#ifndef _LIBCPP_NO_RTTI
     virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
+#endif
 private:
     virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
 };