musllibc does not implement GLOB_ALTDIRFUNC, so do not call
glob for remote sides when libc is musl.
test_e2e.py skips test_glob_src_path when running on alpine.
Previously wrapper functions for open(), opendir(), and stat(), etc,
are implemneted in path.h, and now they are in fileops.h and fileops.c.
This commit is a reparation for remote glob.