Merge branch 'BTF-map-in-map'

Andrii Nakryiko says:

====================
This patch set teaches libbpf how to declare and initialize ARRAY_OF_MAPS and
HASH_OF_MAPS maps. See patch #3 for all the details.

Patch #1 refactors parsing BTF definition of map to re-use it cleanly for
inner map definition parsing.

Patch #2 refactors map creation and destruction logic for reuse. It also fixes
existing bug with not closing successfully created maps when bpf_object map
creation overall fails.

Patch #3 adds support for an extension of BTF-defined map syntax, as well as
parsing, recording, and use of relocations to allow declaratively initialize
outer maps with references to inner maps.

v1->v2:
  - rename __inner to __array (Alexei).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/bpf_helpers.h

@@ -12,6 +12,7 @@
 
 #define __uint(name, val) int (*name)[val]
 #define __type(name, val) typeof(val) *name
+#define __array(name, val) typeof(val) *name[]
 
 /* Helper macro to print out debug messages */
 #define bpf_printk(fmt, ...)				\