Revert "Update aosp/master libcxx rebase to r263688"

The world is burning.

This reverts commit c004fd909c006eec55077c52ee119e1fa338c9e9, reversing
changes made to 1418e4163da4bb0b9e3fe496e51c23a0dce399d9.
diff --git a/test/std/containers/sequences/array/array.size/size.pass.cpp b/test/std/containers/sequences/array/array.size/size.pass.cpp
index a833fdc..89b893a 100644
--- a/test/std/containers/sequences/array/array.size/size.pass.cpp
+++ b/test/std/containers/sequences/array/array.size/size.pass.cpp
@@ -14,9 +14,7 @@
 #include <array>
 #include <cassert>
 
-// std::array is explicitly allowed to be initialized with A a = { init-list };.
-// Disable the missing braces warning for this reason.
-#include "disable_missing_braces_warning.h"
+#include "../suppress_array_warnings.h"
 
 int main()
 {