selftests/bpf: Convert glob_match() to bpf arena

selftests/bpf: Convert glob_match() to bpf arena

Increase arena test coverage.
Convert glob_match() to bpf arena in two steps:
1.
Copy paste lib/glob.c into bpf_arena_strsearch.h
Copy paste lib/globtests.c into progs/arena_strsearch.c

2.
Add __arena to pointers
Add __arg_arena to global functions that accept arena pointers
Add cond_break to loops

The test also serves as a good example of what's possible
with bpf arena and how existing algorithms can be converted.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251111032931.21430-1-alexei.starovoitov@gmail.com