bpftool: Recognize insn_array map type

Teach bpftool to recognize instruction array map type.

Signed-off-by: Anton Protopopov <[e-mail]>
Acked-by: Quentin Monnet <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexei Starovoitov <[e-mail]>

tools/bpf/bpftool/Documentation/bpftool-map.rst

···
 |     | **devmap** | **devmap_hash** | **sockmap** | **cpumap** | **xskmap** | **sockhash**
 |     | **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage**
 |     | **queue** | **stack** | **sk_storage** | **struct_ops** | **ringbuf** | **inode_storage**
-|     | **task_storage** | **bloom_filter** | **user_ringbuf** | **cgrp_storage** | **arena** }
+|     | **task_storage** | **bloom_filter** | **user_ringbuf** | **cgrp_storage** | **arena**
+|     | **insn_array** }
 
 DESCRIPTION
 ===========

tools/bpf/bpftool/map.c

···
 		"                 devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n"
 		"                 cgroup_storage | reuseport_sockarray | percpu_cgroup_storage |\n"
 		"                 queue | stack | sk_storage | struct_ops | ringbuf | inode_storage |\n"
-		"                 task_storage | bloom_filter | user_ringbuf | cgrp_storage | arena }\n"
+		"                 task_storage | bloom_filter | user_ringbuf | cgrp_storage | arena |\n"
+		"                 insn_array }\n"
 		"       " HELP_SPEC_OPTIONS " |\n"
 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
 		"",