as370: -a listing renders LTORG at the pre-alignment LOC and mis-numbers literal-pool entries

[mgrossmann]

Summary

In the -a listing, the LTORG directive line shows the location counter before the literal pool's doubleword alignment, and the literal-pool entries are assigned statement numbers out of source order. The object deck is correct (pool doubleword-aligned, literals at the right offsets); only the listing diverges from IFOX00.

Found while building the #21 pin-deck test; pre-existing (reproduces on as370 without the #21 change), listing-only.

Reproducer

FOO      CSECT
         USING FOO,12
         L     1,=F'9'
LABX     DS    F
         LTORG
         END

as370 -a vs IFOX00

IFOX00:                              as370 -a:
000020  ... 23 LABX  DS F            000020  ... 23 LABX  DS F      (ok)
000028  ... 24 LTORG                 000024  ... 24 LTORG          <- pre-alignment LOC (pool is at 0x28)
000028  ... 25 =F'9'                 000028  ... 29 =F'9'          <- right LOC, wrong stmt number

The pool is doubleword-aligned to 0x28 in both object decks (a 4-byte gap after LABX at 0x20-0x23), but as370's listing prints the LTORG line's LOC as the un-aligned 0x24. The literal entries also get statement numbers assigned after the rest of the module rather than immediately after LTORG.

Impact / scope

Listing-only cosmetic; the object deck (pool alignment, literal offsets, and every reference to a literal) is correct. Out of scope for #21 (that fix touches operand addressability, not LTORG/literal listing). Filed so the #21 listref case can exclude the LTORG region with a reference to this issue rather than silently masking it.

Related: #24 (a sibling -a rendering gap, DS inside a DSECT).