Improve configure's large-file support control.
Description:
Modified configure to now attempt to add defines necessary for
supporting largefiles on all systems, instead of solely on linux. This
is in response to user requests to enable largefile support on Solaris
by default, as well as to give extra control on AIX (instead of just
jamming the necessary flag into the config files).
The old --enable-linux-lfs flag has been removed in favor of the
--enable-largefile flag (enabled by default), which can be used on all
platforms.
On systems where large files cannot be supported in this manner,
configure will report as such.
Tested:
h5committest
AIX (NCSA's blue_print machine)
duty, liberty, and linew.
When gcc is used in the AIX platform, it failed to compile tconfig.c
because it does not recognize the __int64 type. The ibm-aix has the
sizeof __int64=8 cached, as if all compilers supported this type.
Solution:
Removed the cached value for the sizeof __int64 so that during
configure, gcc can report it does not support it and not to use
it in the source code.
Tested:
NCSA Blue which is an AIX machine, using gcc or xlc compiler.
(The gcc still have failure but is being fixed as separated bugs.)
