snapshot bootstrap failure: -march=pentiumpro

[N8TM at aol dot com]

I've stepped through the snapshots and determined that the last snapshot which
was able to bootstrap (on i686-pc-linux-gnulibc1) with BOOT_CFLAGS='-Os
-march=pentiumpro' was egcs-19981026.  I have been unable to isolate which of
the patches added to make up the 19981101 version might be blamed for the
subsequent problem.

For those who haven't seen it, this failure occurs at least on the following
platforms;
both Pentium Pro and Pentium 2
i686-pc-linux-gnulibc1
cygwin-b19 through b20.1, both NT4 and W95

Description:  the compiler built at stage 1 fails with access violation, or
the linux equivalent, while attempting to compiler _divdi3.  Same thing with
either -O2 or -Os together with -march=pentiumpro, with or without additional
options.

Apparently, it may be necessary for someone able to step through the patches
on CVS to determine which one caused this.

For those who don't remember, the 19981026 snapshot had a large number of
changes, the g++ libraries would not build on many platforms, and the compiler
itself would not build on cygwin32.  I suppose it's possible that the bug was
there waiting to be brought out of hibernation by other fixes.