Merge branch 'bpf-multi-prog-improvements'

Sandipan Das says:

====================
[1] Support for bpf-to-bpf function calls in the powerpc64 JIT compiler.

[2] Provide a way for resolving function calls because of the way JITed
    images are allocated in powerpc64.

[3] Fix to get JITed instruction dumps for multi-function programs from
    the bpf system call.

[4] Fix for bpftool to show delimited multi-function JITed image dumps.

v4:
 - Incorporate review comments from Jakub.
 - Fix JSON output for bpftool.

v3:
 - Change base tree tag to bpf-next.
 - Incorporate review comments from Alexei, Daniel and Jakub.
 - Make sure that the JITed image does not grow or shrink after
   the last pass due to the way the instruction sequence used
   to load a callee's address maybe optimized.
 - Make additional changes to the bpf system call and bpftool to
   make multi-function JITed dumps easier to correlate.

v2:
 - Incorporate review comments from Jakub.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>