Update to kernel headers v4.7.2.

Modify the kernel header update script to rename C++ keyword
struct members to something else. This fixes problems when including
these kernel files in C++ code.

Also, make a manual change to linux/fib_rules.h and comment out the
value FRA_PAD since it conflicts with a special android kernel value
FRA_UID_START that has not been upstreamed yet.

Test: Built aosp_angler, aosp_x86_64, aosp_mips (bionic only)
Test: Booted on angler and ran bionic unit tests
Test: Built these changes in internal master

Change-Id: Ia22b7e3ca409404696dba76311f49157f4a9ceed
diff --git a/libc/kernel/uapi/asm-x86/asm/unistd_64.h b/libc/kernel/uapi/asm-x86/asm/unistd_64.h
index 2d02d21..c43d336 100644
--- a/libc/kernel/uapi/asm-x86/asm/unistd_64.h
+++ b/libc/kernel/uapi/asm-x86/asm/unistd_64.h
@@ -426,4 +426,8 @@
 #define __NR_membarrier 324
 #define __NR_mlock2 325
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define __NR_copy_file_range 326
+#define __NR_preadv2 327
+#define __NR_pwritev2 328
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */