Assorted OS/2 fixes

Assorted OS/2 fixes

In article <9706131709.AA05526@toad.ig.co.uk>,
Tim Bunce  <Tim.Bunce@ig.co.uk> wrote:
> It give me great pleasure to announce the arrival of perl5.004_01.

Thank you for a great job!  You even corrected os2/diff.configure!

Unfortunately, several sections of os2/diff.configure were erroneously
removed, so it will not create a valid config.sh any more (ar used
instead of $ar, and one extra method to extract symbols is not
tried).  Unfortunately, I was away from my development machine, so
could not try it earlier.

A patch to correct this problem, and some other ones, follows.

	a) Missing sections restored;
					os2/diff.configure
	b) my_flock added to os2/os2.c (libc contains a dummy
		implementation only) (switchable off in case CRT DLL
		is fixed in this respect);
					os2/os2ish.h os2/Makefile.SHs os2/os2.c
	c) depending on architecture, waitpid may be implemented or not.
		New define HAS_WAITPID_RUNTIME is added and wait4pid
		corrected correspondingly;
					os2/os2ish.h util.c
	d) if -S was given and the file name contained \ , it was
		nevertheless searched on path;
					perl.c
	e) updated:
					os2/Changes README.os2
	f) by default use better gcc optimization options (as mbeattie
		advices):
					hints/os2.sh

[editor's note: this was applied in the reverse order to one a couple
of commits ago]

p5p-msgid: 1997Jun16.163234.2091727@hmivax.humgen.upenn.edu