branch for PCH GC work

[Neil Booth]

Geoff Keating wrote:-

> 
> The first step in merging the PCH work into current FSF GCC is to
> integrate the garbage collection changes.  This is likely to cause
> quite a bit of instability, so I'm about to create a branch off the
> head of the CVS tree in which to hold this work, called pchgc-branch.
> 
> Once this part is done and integrated back into the tree, the
> remaining PCH work should be able to be done in the mainline.

Geoff,

Are you able to divulge anything about how the implementation of PCH
works?  Or is it still some kind of secret (having failed to get
anything out of you so far...).

Neil.