Implement bpf syscall decoding

* bpf.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* configure.ac (AC_CHECK_HEADERS): Add linux/bpf.h.
* linux/dummy.h (sys_bpf): Remove.
* pathtrace.c (pathtrace_match): Add SEN_bpf.
* xlat/bpf_commands.in: New file.
* xlat/bpf_map_types.in: New file.
* xlat/bpf_map_update_elem_flags.in: New file.
* xlat/bpf_prog_types.in: New file.
* tests/bpf.c: New file.
* tests/bpf.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add bpf.
(TESTS): Add bpf.test.
* tests/.gitignore: Add bpf.
diff --git a/tests/.gitignore b/tests/.gitignore
index 449e64c..98f6e8a 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -1,3 +1,4 @@
+bpf
 caps
 fanotify_mark
 filter-unavailable