Bug in 19980806 and 19980814 snapshots

[David Edelsohn]

	I believe the rs6000 port was change in this area since egcs-1.0.
Depending on what compiler and version you were using as a base to test
your changes and when, this error may not have occurred when testing on
AIX a while ago.

	I just worry that all of these individual macros you need to fake
out the normal backend macros defined by various ports will be a
maintenance problem for both you and port maintainers.  I realize that
there is not much way around it, especially given what Objective C is
trying to accomplish.  Even defining all current TREE and TYPE macros
fails if new ones are added because they are needed by a new target.
Either the person maintaining Objective C or individual port maintainers
probably are going to hit similar problems again with other changes whose
impact upon encoding.c is not known.

David