mainline patch for issue info

[Jeffrey A Law]

  In message < 19980818124831.A10127@dot.cygnus.com >you write:
  > I've worked up a patch for Alpha to align instruction groups
  > properly so that they may be slotted and issued in the same cycle.
  > 
  > To do this well, I need additional info from Haifa, describing what
  > it expects to be able to simultaneously issue.  I accomplish this
  > by marking instructions that begin a group with TImode.  This does
  > of course clobber the annotations reload left; for that reason I
  > don't add this info for machines that can't dual issue at all.
I do not believe anything after reload depends on those annotations,
so I guess it's OK.

You should update rtl.texi though since it discusses the meaning of
QI/HI mode on an INSN.  You should also mention that the target files
may depend on this mode to be preserved and that passes after sched
should not alter the mode of an INSN.

jeff