TARGET_PC Increase real shadow pool from 8 to 16

[RgeditV1]

fix: #2653

The real shadow system (dDlst_shadowReal_c) is limited to 8 slots per frame (mReal[8], packed 4-per-channel into mShadowTexObj[2]). Once the pool is full, dDlst_shadowControl_c::setReal evicts the farthest entry in the z-sorted lis or drops the new shadow entirely if it is farther than all existing ones

Because eviction is driven by getCameraZ(), the missing shadows change with the camera angle. With ~8–10 shadowed actors on screen (e.g. NPCs/cats in a scene (even link lost his shadow)), 5+ of them intermittently lose their shadows.

some escenarios

include/d/d_drawlist.h:

• Add REAL_SHADOW_MAX = 16 and REAL_SHADOW_TEX_NUM = REAL_SHADOW_MAX / 4 constants.
• Resize mReal[8] → mReal[REAL_SHADOW_MAX].
• Resize mShadowTexObj[2] / mShadowTexData[2] → [REAL_SHADOW_TEX_NUM] (4).

src/d/d_drawlist.cpp:

• init(): l_realImageSize expanded to REAL_SHADOW_TEX_NUM entries
  ({192, 192, 64, 64} — keeps the original large/small split), loop bound updated.
• reset(): loop bound 8 → REAL_SHADOW_MAX.
• setReal(): pool-full check and free-slot scan 8 → REAL_SHADOW_MAX.

Each dDlst_shadowReal_c is ~9.5 KB (mShadowTri[256]), so this adds ~76 KB more or less to
dDlst_shadowControl_c / dDlst_list_c. Acceptable for the fix i think no?

its need more testing, if someone can helpme this is the way

• Reproduce scene with 10+ shadowed NPCs; all shadows visible regardless of camera angle.
• Verify no regression in imageDraw texture packing for <8 and 9–16 shadows.
• Check distance culling path (dVar17 < -1000) still drops far shadows correctly.