Revert "[libc++] Only include_next C library headers when they exist"
This reverts commit 226409c62879bf5ff9928cd23a4255cd7c614fe0.
Breaks check-clang on mac, see comments on https://reviews.llvm.org/D136683
NOKEYCHECK=True
GitOrigin-RevId: 674729813e3be02af7bda02cfe577398763f58b9
diff --git a/include/string.h b/include/string.h
index 627cbae..082c632 100644
--- a/include/string.h
+++ b/include/string.h
@@ -57,9 +57,7 @@
# pragma GCC system_header
#endif
-#if __has_include_next(<string.h>)
-# include_next <string.h>
-#endif
+#include_next <string.h>
// MSVCRT, GNU libc and its derivates may already have the correct prototype in
// <string.h>. This macro can be defined by users if their C library provides