egcs-19980628 and limits.h

[Joel Sherrill <joel at OARcorp dot com>]

It appears the between egcs 1.0.3 and egcs-19980628 that the definition of
SYSTEM_HEADER_DIR changed from:

SYSTEM_HEADER_DIR = $(tooldir)/include

to

SYSTEM_HEADER_DIR = $(tooldir)/sys-include

This has broken RTEMS installation of limits.h.  RTEMS' system limits.h is
in newlib and although there are build ordering problems, it does end up
in $(tooldir)/include which trips the "limits.h exists" path.

Any ideas on how to address this other than to "pre-install" 
$(tooldir)/sys-include/limits.h before beginning a build?  Doing this
feels like a kludge but works.  To prevent having to add sys-include to
the include path, I would still let the regular newlib install process put
limits.h in the $(tooldiir)/include directory. 

Comments appreciated.  My impression is that the new scheme is OK for
Canadians but may require some presetup for embedded crosses.  It would be
cool if newlib new what to do to get its header files in place before gcc
ran.

--joel