needless deep recursion in gt-c-decl.h

[David Edelsohn]

>>>>> Per Bothner writes:

Per> I'm point point is I'm not sure a two-loop algorithm is needed.
Per> I got the impression is that the one-loop argorithm doesn't work
Per> for trees because of references from trees to rtl, like DECL_RTL.
Per> I don't understand how rtl to the same extent, but I also think
Per> a single loop should be enough to avoid deep recursion.

Per> I'm just concerned about slowing down gcc bit by bit.

	Does GCC always do the marking or only when PCH will be enabled?

David