...since the implementation is BSD. I missed this in the original code
review (and the presubmit hooks were skipped, so the machines didn't
notice).
Test: N/A
Change-Id: Ia9fe067c68b3ab8045d3f5dfe256f3200f102fbf
musl libc doesn't provide fts, but elfutils and libabigail need it.
Export bionic's fts as a staic library that can be linked into elfutils
and libabigail when compiling against musl.
fts uses recallocarray, which musl doesn't provide, so also include
recallocarray.c in libfts.a.
Requires minor tweaks to fts.c and a wrapper around fts.h to make them
compatible with musl, primarily by providing local definitions of macros
provided in bionic's sys/cdefs.h.
Bug: 190084016
Test: m libfts
Change-Id: Ifac9a59e7504c0c1f5f8a3a5bd3c19a13980b83c
