- add support for using sysconf to get page size in _mallocr.c via
HAVE_SYSCONF_PAGESIZE flag set in configure.host
- set flag in configure.host for arm and add a default sysconf implementation
in libc/sys/arm that returns the page size
- the default implementation can be overridden outside newlib to allow a
different page size to improve malloc on devices with a small footprint
without needing to rebuild newlib
- this patch is based on a contribution from Torbjorn Svensson and
Niklas Dahlquist (https://ecos.sourceware.org/ml/newlib/current/017616.html)
Convert all the libc/ subdir makes into the top-level Makefile. This
allows us to build all of libc from the top Makefile without using any
recursive make calls. This is faster and avoids the funky lib.a logic
where we unpack subdir archives to repack into a single libc.a. The
machine override logic is maintained though by way of Makefile include
ordering, and source file accumulation in libc_a_SOURCES.
There's a few dummy.c files that are no longer necessary since we aren't
doing the lib.a accumulating, so punt them.
The winsup code has been pulling the internal newlib ssp library out,
but that doesn't exist anymore, so change that to pull the objects.