[AGC] Quake rendering progress: WAIT_REG_MEM, draw fixes, VideoOut, and HLE improvements (#68)

* [agc] WAIT_REG_MEM suspend/resume, draw packet fixes, new HLE exports, debug cleanup

Rebased onto upstream 79a7437 (par274/sharpemu, rewritten history).

- GpuWaitRegistry: DCBs suspended on unsatisfied WAIT_REG_MEM are re-polled
  against guest memory on every submit; fixed 64-bit and standard packet parse
  offsets, apply the mask, treat PM4 compare function 0 as "always".
- TryReadSubmittedDrawCount: accept the 5-dword ItDrawIndex2 form emitted by
  DcbDrawIndex (count at +4); menu draws were silently discarded before.
- sceAgcDriverSubmitMultiDcbs: reversed ABI (rdi=address array, rsi=dword
  sizes, rdx=count).
- VideoOut: vblank events, sceVideoOutGetFlipStatus, buffers registered via
  sceVideoOutRegisterBuffers are valid flip targets.
- New HLE: libc stdio (fopen/fread/fseek/ftell/fclose/fgets), Dinkumware
  _Getpctype ctype table, NpTrophy2 stubs, AMPR PAK sequential-read tracker,
  MsgDialog lifecycle, NGS2 alt NIDs + dummy vtable for handle objects,
  guarded memset intrinsic, abort()/strcasecmp null-arg recovery.
- Removed investigation-only code (INT3 breakpoints, qfont/mcpp dumps,
  error-candidate printf traces, unconditional debug logs).

First rendered frame: Quake (PPSA01880) presents a 1920x1080 guest frame.

* Implemented a guarded native intrinsic (rep movsb) in DirectExecutionBackend to bypass HLE dispatch overhead, while preserving memory safety checks.

src/SharpEmu.Libs/CxxAbiExports.cs

@@ -93,7 +93,7 @@ public static class CxaGuardExports
     }
 
     [SysAbiExport(
-        Nid = "",
+        Nid = "9rAeANT2tyE",
         ExportName = "__cxa_guard_release",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libc")]
@@ -142,7 +142,7 @@ public static class CxaGuardExports
     }
 
     [SysAbiExport(
-        Nid = "",
+        Nid = "2emaaluWzUw",
         ExportName = "__cxa_guard_abort",
         Target = Generation.Gen4 | Generation.Gen5,
         LibraryName = "libc")]