Add sys/stat.h compatibility macros for old NDKs.

Test: make checkbuild
Bug: https://github.com/android-ndk/ndk/issues/417
Change-Id: I04fdb2f31131e87907adab9f3264b783917de542
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index f8d854d..47ff5c4 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -127,6 +127,10 @@
 #define st_atimensec st_atim.tv_nsec
 #define st_mtimensec st_mtim.tv_nsec
 #define st_ctimensec st_ctim.tv_nsec
+/* Compatibility with Linux headers and old NDKs. */
+#define st_atime_nsec st_atim.tv_nsec
+#define st_mtime_nsec st_mtim.tv_nsec
+#define st_ctime_nsec st_ctim.tv_nsec
 
 #if defined(__USE_BSD)
 /* Permission macros provided by glibc for compatibility with BSDs. */