Update to v4.15 kernel headers.

Test: Compiles, boots bullhead/hikey960.
Change-Id: I118beb8b6cac0881b1270f9bf6981959297a41a8
diff --git a/libc/kernel/uapi/asm-generic/bpf_perf_event.h b/libc/kernel/uapi/asm-generic/bpf_perf_event.h
new file mode 100644
index 0000000..794927b
--- /dev/null
+++ b/libc/kernel/uapi/asm-generic/bpf_perf_event.h
@@ -0,0 +1,23 @@
+/****************************************************************************
+ ****************************************************************************
+ ***
+ ***   This header was automatically generated from a Linux kernel header
+ ***   of the same name, to make information necessary for userspace to
+ ***   call into the kernel available to libc.  It contains only constants,
+ ***   structures, and macros generated from the original header, and thus,
+ ***   contains no copyrightable information.
+ ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
+ ****************************************************************************
+ ****************************************************************************/
+#ifndef _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__
+#define _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__
+#include <linux/ptrace.h>
+typedef struct pt_regs bpf_user_pt_regs_t;
+#endif