Failed build of egcs-980411 on SGI/IRIX-6.5

[Jim Wilson]

	a) when using "--enable-threads", the first stage
	   of "gmake bootstrap" fails because the file
	   "gthr-irix.h" is missing.

No one has contributed this file yet.  Someone who understands the irix
thread support will need to write the stub routines needed in this file.
If there is no such thing as `irix' threads, and we should instead be using
posix threads, or pthreads, or something else that is already supported,
then that would be easy to fix.

	b) without "--enable-threads", the second stage
	   fails with an "internal compiler error:

The C++ front end is broken.  Almost everyone has run into this.  Hopefully
it will be fixed in time for the next snapshot.

Jim