[m-dev.] diff: runtime clean-ups

[Zoltan Somogyi]

> runtime/mercury_table.h:
> runtime/mercury_table.c:
> 	Delete these empty files.
> 	For some reason zs left these files as empty instead of deleting
> 	them when he renamed the module as mercury_hash_table.{h,c}.

The reason I left them empty is that we may want to use those file names
again, and CVS does not properly handle files that are deleted and then
added back again.

Zoltan.