[PATCH] Unify tree/RTL dump file handling (1/5)

[Paolo Bonzini]

> While we're on the subject, the .*.rtl dump is broken, and
> pass_expand doesn't get any sort of dump associated with it.
> Both of which are annoying for debugging rtl expansion.

All of -da, -fdump-rtl-expand, -dr produce a *.00.expand file for me.

 > From my point of view, the ideal resolution would be that the
 > debug output from pass_expand would wind up in the .*.rtl dump file.

The name was changed from *.rtl exactly because it is now the 
interleaved GIMPLE/RTL dump that cfgexpand.c is equipped to produce.

Paolo