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/ucontext.h b/libc/kernel/uapi/asm-x86/asm/ucontext.h
index 9ceffac..88f8160 100644
--- a/libc/kernel/uapi/asm-x86/asm/ucontext.h
+++ b/libc/kernel/uapi/asm-x86/asm/ucontext.h
@@ -19,6 +19,11 @@
 #ifndef _ASM_X86_UCONTEXT_H
 #define _ASM_X86_UCONTEXT_H
 #define UC_FP_XSTATE 0x1
+#ifdef __x86_64__
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define UC_SIGCONTEXT_SS 0x2
+#define UC_STRICT_RESTORE_SS 0x4
+#endif
 #include <asm-generic/ucontext.h>
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif