Exceptions: the "gij bug"

[Alexandre Petit-Bianco]

Tom Tromey writes:

> The Java front end has not been updated to use ggc.  I imagine we'll
> do this someday, but I don't know when.

Right. I talked about it with Richard Henderson and Jeff Law a while
ago. We realized that our one-tree-node-per-class-that-holds-everything
approach makes it easy to use the GC, we might just have to register
the classes that are retained for code generation (they're stored in a
list) as roots. We might have cases of bad hacks around, like storing
a rtx in a tree node.

And then we should be able to get rid of the obstack management code.

./A