Revert "fixup: log array argument"

This reverts commit 24b91868d87fa054c2fd0daf95a3dad2749970cc.

Turns out logging MDefinition addresses is not useful. First, they're
too fine grained to use for merging; the same array can have multiple
MDefinitions (intervening writes, we're in SSA). Second, they're not the
same across compiles (which makes sense), which again prevents merging
(and makes locations look different, which defeats even more basic
merging).