internal_reference_types

[Richard Kenner]

> Yes, the address space stuff is posterior, but the Pmode thing is verbatim.

Doesn't ring a bell.  Sorry.  I don't even remember what the other
option would be other than Pmode.

> REFERENCE_TYPEs and POINTER_TYPEs are (should be) treated almost equally in 
> the compiler, the difference matters only for the debug info.  We use the 
> former much more now than we used to in gigi, because of the debug info.

Right.  The transition to using REFERENCE_TYPEs more started back in my time.