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/testit b/test/testit
index cac6684..821292e 100755
--- a/test/testit
+++ b/test/testit
@@ -42,7 +42,7 @@
 fi
 if [ -z "$OPTIONS" ]
 then
-	OPTIONS="-std=${CXX_LANG} -stdlib=libc++ -nostdinc++"
+	OPTIONS="-std=${CXX_LANG} -stdlib=libc++"
 fi
 OPTIONS="$OPTIONS -I$LIBCXX_ROOT/test/support"