selftests/bpf: Convert glob_match() to bpf_arena

Step 1:
Copy paste lib/glob.c into bpf_arena_strsearch.h
Copy paste lib/globtests.c into progs/arena_strsearch.c

Step 2:
Add __arean to pointers
Add __arg_arena to global functions that accept arena pointers
Add cond_break to loops

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