[Bug fortran/53456] Add time support for VxWorks

["rbmj at verizon dot net" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53456

--- Comment #4 from rbmj at verizon dot net 2012-05-23 13:10:14 UTC ---
VxWorks does not provide the process time in most versions and for most cases. 
In fact, many VxWorks applications are not processes in the traditional sense
but instead tasks/threads spawned by the kernel in kernel space.

If returning an error is the preferred behavior for gf_cputime, then the code
as is should work.  But it doesn't seem optimal (IMHO) to only have second
resolution for gf_gettime.  If that is OK though, and preferable to introducing
new code (I could understand why), then that is fine too.

Also, I started working on this before realizing that the reason it failed to
compile initially was mis-configuration.  It should compile as-is, just not
work as well as (I believe) it could.