t/op/sigdispatch.t: Increase timeout to avoid issues on slow processors
hints/linux-androideabi.sh: use randfunc=random and randbits=31
On Android, set $ENV{TMPDIR} on the tests for open($fh, undef)

This is primarily to get the tests working. open($fh, undef) calls
PerlIO_tmpfile(), which requires either /tmp to exist or $ENV{TMPDIR}
to be set.  In Android, neither of those is true.

A possible fix would be to have PerlIO_tmpfile() behave like File::Temp
and just try the cwd; the "real" fix would require calling java
at startup to get Context.getCacheDir.
dist/IO/t/io_pipe.t: Work around android only having an inbuilt echo
Perl::OStype: Report Android as a Unix-like OS.
perlio.c, PerlIO_tmpfile: Fall back to cwd if we have no /tmp or TMPDIR
ext/POSIX/t/time.t: Conditionalize the use of setlocale/LC_TIME

On Android, all locales are simply disabled, which broke the assumption
that LC_TIME is always available.
ext/POSIX/t/sysconf.t: Skip testing pathconf with _PC_LINK_MAX on android
cpan/Sys-Syslog/Syslog.pm: Conditionalize the use of setlocale/LC_TIME
perlport open fixup
Android hints: Detect stub functions and mark them as undefined.

Bionic implements several functions as stumps that simply warn
and return null, which leads to situations like this:

FIX ME! implement getprotobyname() bionic/libc/bionic/stubs.c:378

This commit introduces some probes for functions (getnetbyname,
getnetbyaddr, getmntent, getprotobyname, getprotobynumber, endpwent,
ttyname) that we use and are actually stubs in at least some
versions of Android.
If we find a stub, we pretend that the function is undefined, so
the above example becomes this:

Unsupported socket function "getprotobyname" called at -e line 1.

Note that this commit does not fix the modules that assume that
these functions are always available, so 'make test' still fails.
Net::Ping: Handle getprotobyn{ame,umber} not being available
Sys::Syslog: handle getprotobyn{ame,umber} not being available (cpan)
IO::Socket::INET: Handle getprotobyn{ame,umber} not being available