Integrate perlio:

Integrate perlio:

[  9322]
Routine Win32 regen_config_h - no real changes.

[  9321]
PerlIO fixups for Win32:
- provide win33_popenlist() - non-functional as yet.
- avoid need for aTHX in PerlIO_debug calls - even if not
enabled args are still evaluated so Win32 has trouble during fork().
- Add PerlIO/Scalar to list of extensions in win32/makefile.mk
- Fixup makedef.pl for latest set of symbols.

[  9320]
POSIX::getcwd XS code to call Cwd::cwd when HAS_GETCWD not defined
was gibberish - broke it on WIn32 at least.

[  9319]
Generated files.

[  9318]
Implement:
1.  open($fh,"+<",undef);  # add test to t/io/open.t
2.  open($fh,"+<",\$var);  # New test t/lib/io_scalar.t

p4raw-link: @9322 on //depot/perlio: e009d45070febfef5a59a9468c3cb4e6ad05051f
p4raw-link: @9321 on //depot/perlio: 8c0134a884f927d58f584b87281e5a27133cbf8f
p4raw-link: @9320 on //depot/perlio: 5dd1177c222be3aa5f44de160a952953bc5703a5
p4raw-link: @9319 on //depot/perlio: c60e0e098045567c2313456d074b4094292b050c
p4raw-link: @9318 on //depot/perlio: f6c77cf1bf4d7cb2c7a64dd7608120b471f84062

p4raw-id: //depot/perl@9323