New branch for GC work

["Laurynas Biveinis" <laurynas dot biveinis at gmail dot com>]

Hello,

Since mainline is in, or is about to enter very soon, stage 3, I have
created a new branch "gc-improv" for GC work and related changes that
are not strictly bug fixes. The difference from the old boehm-gc
branch is that this one will not contain Boehm's GC integration.

As my previous email http://gcc.gnu.org/ml/gcc/2007-09/msg00144.html
did not receive any feedback, I assume that the plan there is OK and I
will proceed according to it:

- Take at least one more allocation site out of GC to pool or obstack;
- The "easy" parts of the last week's NEXT_INSN = NULL trainwreck;
- Couple more fixes/cleanups.
These will be submitted to mainline on stage1/stage2.

The interesting parts, already implemented in boehm-gc branch:
- gengtype changes to generate separate GC allocators for each used type
- convert GCC to use these
- add type-tags to objects

Then
- New GC marker, using type-tags.

I will document the gc-improv branch in svn.html shortly. Boehm-gc
will stay in the list of active branches until I finish porting over
stuff from it.

Any comments about the plan are still very welcome :)

-- 
Laurynas