Update to v4.19 kernel headers.

Test: Builds and boots.
Change-Id: I99a9ed79666e143b47f02ca4e59eed94f69b7e4a
(cherry picked from commit a981e2e52e2e95a65fa9c9b6fb16dcb4c83dd576)
diff --git a/libc/kernel/uapi/asm-x86/asm/unistd_x32.h b/libc/kernel/uapi/asm-x86/asm/unistd_x32.h
index e10cc6b..b5f3fb1 100644
--- a/libc/kernel/uapi/asm-x86/asm/unistd_x32.h
+++ b/libc/kernel/uapi/asm-x86/asm/unistd_x32.h
@@ -304,6 +304,8 @@
 #define __NR_pkey_alloc (__X32_SYSCALL_BIT + 330)
 #define __NR_pkey_free (__X32_SYSCALL_BIT + 331)
 #define __NR_statx (__X32_SYSCALL_BIT + 332)
+#define __NR_io_pgetevents (__X32_SYSCALL_BIT + 333)
+#define __NR_rseq (__X32_SYSCALL_BIT + 334)
 #define __NR_rt_sigaction (__X32_SYSCALL_BIT + 512)
 #define __NR_rt_sigreturn (__X32_SYSCALL_BIT + 513)
 #define __NR_ioctl (__X32_SYSCALL_BIT + 514)