tools lib bpf: fixes and functional upgrade

Hello,

Here's a patchset on the libbpf library that can be found in tools/lib/bpf.

Patch 0 to patch 4 add a new function to be able to set the BPF program type. Till then program type such as network filter can't be loaded by the library:

* tools lib bpf: add error functions
* uapi linux bpf: add max value to enum
* tools: Sync tools/include/uapi/linux/bpf.h with the
* tools lib bpf: export function to set type

Patch 5 is adding functions that were missing to handle maps in userspace.

* tools lib bpf: add missing functions

Patch 7 fixes a bug in the parsing of BPF ELF file.

* tools lib bpf: fix maps resolution

Patch 8 update 'make install' to install the header on the system.

* tools lib bpf: install header file

Patchset statistics:

 include/uapi/linux/bpf.h       |  1 +
 tools/include/uapi/linux/bpf.h | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 tools/lib/bpf/Makefile         | 11 +++++++++--
 tools/lib/bpf/bpf.c            | 35 ++++++++++++++++++++++++++++++++++-
 tools/lib/bpf/bpf.h            |  2 --
 tools/lib/bpf/libbpf.c         | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------
 tools/lib/bpf/libbpf.h         | 12 +++++++++++-
 7 files changed, 166 insertions(+), 34 deletions(-)

Best regards,