Update libc/hdr/offsetof_macros.h

Co-authored-by: Michael Jones <[email protected]>

Author: SchrodingerZhu

libc/hdr/offsetof_macros.h

@@ -9,7 +9,15 @@
 #ifndef LLVM_LIBC_HDR_OFFSETOF_MACROS_H
 #define LLVM_LIBC_HDR_OFFSETOF_MACROS_H
 
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/offsetof-macros.h"
+
+#else // Overlay mode
+
 #define __need_offsetof
 #include <stddef.h>
 
+#endif // LLVM_LIBC_FULL_BUILD
+
 #endif // LLVM_LIBC_HDR_OFFSETOF_MACROS_H