bpf: sync with latest bpf-next tree (#5)

sync with latest bpf-next tree.
the include/linux/filter.h is created as libbpf.c tries
to use various insn define macros.

Signed-off-by: Yonghong Song <yhs@fb.com>

include/linux/filter.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+#ifndef __LINUX_FILTER_H
+#define __LINUX_FILTER_H
+
+#include <linux/bpf.h>
+
+#define BPF_MOV64_IMM(DST, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+#define BPF_EXIT_INSN()						\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_EXIT,			\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#endif