Decomp five more leftover single-function asm files

Second cleanup sweep. Each was the only function left in its own asm file, so
each removes an asm file and its include:

  asm/overlay_29_0234B0CC.s   SetMessageLogPreprocessorArgsStringToName
  asm/overlay_29_023268CC.s   DoMoveSmokescreen
  asm/overlay_29_02325F74.s   DoMoveMorningSun
  asm/overlay_29_02326E20.s   DoMoveGust
  asm/overlay_29_022EA980.s   GenerateDungeonRngSeed

Two needed a second reading:

- DoMoveGust doubles the damage multiplier when the defender's
  bide_class_status.bide is 7 or 8. The target tests it as a byte with
  `add #0xF9`, so the source adds 0xF9 rather than subtracting 7; `- 7` compiles
  to `sub #7` and does not match.
- GenerateDungeonRngSeed runs the LCG twice, stores the second result back to
  prng_state::preseed, and returns the two halves recombined. The operand order
  in the final or-expression decides whether the mask or the shift is scheduled
  first; taking the shifted half first matches.

Authored by Claude (Opus 5) under human direction. All five verified at score 0.
Confirmed by a matching build: build/pmdsky.us/pmdsky.us.nds: OK. None carries a
region conditional, so US alone is sufficient.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

asm/include/overlay_29_022EA980.inc

@@ -1,2 +0,0 @@
-#pragma once
-.public DUNGEON_PRNG_STATE

asm/include/overlay_29_02325F74.inc

@@ -1,4 +0,0 @@
-#pragma once
-.public GetApparentWeather
-.public MORNING_SUN_HP_RESTORATION_TABLE
-.public TryIncreaseHp

asm/include/overlay_29_023268CC.inc

@@ -1,4 +0,0 @@
-#pragma once
-.public CalcStatusDuration
-.public SMOKESCREEN_TURN_RANGE
-.public TryInflictWhifferStatus

asm/include/overlay_29_02326E20.inc

@@ -1,2 +0,0 @@
-#pragma once
-.public DealDamage

asm/include/overlay_29_0234B0CC.inc

@@ -1,4 +0,0 @@
-#pragma once
-.public GetName
-.public GetSize0x80Buffer
-.public MESSAGE_LOG_INFO