add new syscall numbers for bpf and kexec_file_load

these syscalls are new in linux v3.18, bpf is present on all
supported archs except sh, kexec_file_load is only allocted for
x86_64 and x32 yet.

bpf was added in linux commit 99c55f7d47c0dc6fc64729f37bf435abf43f4c60

kexec_file_load syscall number was allocated in commit
f0895685c7fd8c938c91a9d8a6f7c11f22df58d2
diff --git a/arch/i386/bits/syscall.h b/arch/i386/bits/syscall.h
index 7584f30..2378053 100644
--- a/arch/i386/bits/syscall.h
+++ b/arch/i386/bits/syscall.h
@@ -355,6 +355,7 @@
 #define __NR_seccomp		354
 #define __NR_getrandom		355
 #define __NR_memfd_create	356
+#define __NR_bpf		357
 
 
 /* Repeated with SYS_ prefix */
@@ -716,3 +717,4 @@
 #define SYS_seccomp		354
 #define SYS_getrandom		355
 #define SYS_memfd_create	356
+#define SYS_bpf			357