[Ohrrpgce] SVN: teeemcee/10856 linux: restore portable=1 support for glibc as old as 2011 when compilin

[subversion at HamsterRepublic.com]

teeemcee
2018-11-08 05:34:56 -0800 (Thu, 08 Nov 2018)
435
linux: restore portable=1 support for glibc as old as 2011 when compiling against latest glibc version 2.28

2.28 defines new fcntl and fcntl64 functions and since these are used in libfb
I had to use a ld hack to wrap and redirect these to the old fcntl symbol.

Also I replaced fmemopen with open_memstream (both are POSIX-2008 functions)
because fmemopen also has a recent symbol version problem. And open_memstream
is nicer anyway.
---
U   wip/SConscript
A   wip/lib/wrap_fcntl.c
U   wip/os_unix.c
U   wip/os_unix_wm.c