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/linux/lwtunnel.h b/libc/kernel/uapi/linux/lwtunnel.h
index 9bd438f..bf9b4d2 100644
--- a/libc/kernel/uapi/linux/lwtunnel.h
+++ b/libc/kernel/uapi/linux/lwtunnel.h
@@ -41,21 +41,24 @@
   LWTUNNEL_IP_TOS,
   LWTUNNEL_IP_FLAGS,
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+  LWTUNNEL_IP_PAD,
   __LWTUNNEL_IP_MAX,
 };
 #define LWTUNNEL_IP_MAX (__LWTUNNEL_IP_MAX - 1)
-enum lwtunnel_ip6_t {
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+enum lwtunnel_ip6_t {
   LWTUNNEL_IP6_UNSPEC,
   LWTUNNEL_IP6_ID,
   LWTUNNEL_IP6_DST,
-  LWTUNNEL_IP6_SRC,
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+  LWTUNNEL_IP6_SRC,
   LWTUNNEL_IP6_HOPLIMIT,
   LWTUNNEL_IP6_TC,
   LWTUNNEL_IP6_FLAGS,
-  __LWTUNNEL_IP6_MAX,
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+  LWTUNNEL_IP6_PAD,
+  __LWTUNNEL_IP6_MAX,
 };
 #define LWTUNNEL_IP6_MAX (__LWTUNNEL_IP6_MAX - 1)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif