os_times3.PATCH works for me on Mac OS 10.4 and RHEL.  I have a few 
comments on the patch:

1. sysconf return type is long, not clock_t
2. If sysconf is present, but _SC_CLK_TCK is not supported, it will 
return -1.  In this case we should fall back to system HZ if available.
3. Use -1 instead of NULL as the invalid value. NULL has too strong 
connotation with pointers.
4. On systems where fixed HZ is correct calling sysconf(_SC_CLK_TCK) on 
every times call is an overkill.

I would suggest that instead of patching posixmodule.c an appropriate 
system-dependent value for HZ should be defined in configure.h.  
Unfortunately I am not familiar enough with autoconf to prepare a patch.