swift234

Improve epilogue release matcher to handle exploded release_value.

So instead of only being able to match %1 and release %1 in (1). we
can also match %1 with (release %2, and release%3, i.e. exploded release_value)
in (2).

(1)
foo(%1)
  strong_release %1

(2)
foo(%1)
  %2 = struct_extract %1, field_a
  %3 = struct_extract %1, field_b
  strong_release %2
  strong_release %3

This will allow function signature to better move the release instructions to
the callers.

Currently, this is a NFC other than testing using the epilogue match dumper.