code development

[Stephen Weeks]

> -keep dot can also be helpful, if the graphs aren't to big.
> Unfortunately, the dot layout doesn't have access to the name of the .ssa
> file being produced, so you don't get pre and post versions.  (In fact,
> you only get .dot files for the last ssa layout, which is usually the
> final ssa program when you use -keep ssa.)

I checked in a fix for this.  Now the following command

	mlton -keep-pass removeUnused5 -keep dot z.sml

produces the following files

z.removeUnused5.pre.ssa.main_0.dom.dot
z.removeUnused5.pre.ssa.main_0.cfg.dot
z.removeUnused5.pre.ssa.call-graph.dot
z.removeUnused5.pre.ssa
z.removeUnused5.post.ssa.main_0.dom.dot
z.removeUnused5.post.ssa.main_0.cfg.dot
z.removeUnused5.post.ssa.call-graph.dot
z.removeUnused5.post.ssa