[LLVMdev] Dropping support for llvm-gcc3

[Reid Spencer]

LLVMers,

This doesn't affect release 1.X users, only those using the LLVM current
(CVS head) version.

With recent changes, the current version of LLVM will no longer read old
assembly or bytecode files. The upgrade path from 1.X to 2.0 is now
provided by the new llvm-upgrade tool. See:

http://llvm.org/docs/CommandGuide/html/llvm-upgrade.html

for details on how to use this command.

llvm-gcc3 generates old assembly code that will no longer assemble
correctly when read by gccas.  The change to llvm-gcc3 necessary to get
it to emit the new instruction formats is too complicated since there is
an alternative: llvm-gcc4. Consequently, we are dropping support for
llvm-gcc3 as of today.

How to cope with this change:

1. If you are managing a nightly tester, please have it use llvm-gcc4
instead 
   of llvm-gcc3. If you don't, everything will fail (currently is
failing).
2. If you must use the (really slow) exception handling support in
llvm-gcc3, please
   continue to use LLVM 1.9 until EH support is implemented in 2.0.
3. If you must use llvm-gcc3 for other reasons, it might be possible to
hack it so
   that it runs llvm-upgrade before it runs gccas. If you do this,
please submit the
   patch.

Reid.