[BC ABI] Use PARM_DECLs preferentially

[Tom Tromey]

>>>>> "Andrew" == Andrew Haley <aph@redhat.com> writes:

Andrew> This is for a corner case that tromey found when compiling Eclipse.
Andrew> We were creating a new local variable for a slot that held a parameter
Andrew> in the case where the access was of a different type.
Andrew> Tom, please test this.

I rebuilt all the .jars in Eclipse 2 with this; the result works fine.

Tom