Eliminate level-4 warnings

[Kitsune44]

Eliminate level-4 warnings

Reduces the warning count of src/reactivedrop_vs13.sln from 3,249 lines in Debug|Win32 (17 codes, 824 distinct file:line sites) and 3,161 in Release|Win32 to 5 in both configurations, all of them the C5205 uses documented at the end. The projects keep /W4, do not use /WX, and no warning was disabled, no pragma added and no conformance switch relaxed. Every edit is behaviour preserving.

Warnings were fixed at their root cause where one existed, so that a single declaration or macro covers hundreds of sites, and with an explicit conversion or a scope-local rename otherwise. Edits preserved the existing file encodings (parts of the tree are Windows-1252) and BOMs. A rebuild followed every batch, so that a regression could not hide behind an unrelated diagnostic, and both configurations were finally rebuilt from scratch.

The groups, in descending order of size

1. C5054 (1,868 occurrences / 642 sites), comparisons between two different enumeration types, which C++20 deprecates. Three causes:

   • Classify() returns Class_T while the entity classes of this mod (CLASS_ASW_, CLASS_FUNC_) are a separate anonymous enum that continues the Class_T numbering from LAST_SHARED_ENTITY_CLASS. The enum is now named ASW_Class_T and the intended comparison with Class_T is stated once, as four inline ==/!= operators, instead of converting roughly 585 call sites.

   • ASW_COLLISION_GROUP_* continues Collision_Group_t and SHOULD_COLLIDE()/ASSERT_INVARIANT() compare the two numberings with <=. Those assertions now compare (int) values.

   • Six further sites (the COMPILE_TIME_ASSERT of bits_BUILD_* against bits_CAP_MOVE_, MAX( ASW_NUM_EQUIP_ ), two shadow flag bitmasks and MB_FIELD_TEXCOORD_LAST) take an explicit conversion.

2. C4471 (1,150 / 12), forward declarations of unscoped enumerations without an underlying type: they now name : int, and the two enums that could be defined before their declaration (ASW_Skill, RD_Crafting_Material_t) received the same fixed type in their definition, so declaration order no longer matters. The unused DXGI_FORMAT forward declaration in bitmap/imageformat.h was removed: nothing in the tree refers to it and the DXGI headers define it without an explicit underlying type, so any fixed type would conflict with them.

3. C4456/C4457/C4458/C4459 (112), shadowing of class members, globals, parameters and enclosing locals. The shadowing declaration was renamed inside its own scope only (index -> iIndex, view -> viewSetup, effects -> nEffects, flags -> nFlags, model -> pModel, pRenderContext -> pRenderCtx, ...), leaving access to members and statements preceding the declaration untouched. The five reports in CShadowDepthView::Draw come from VPROF_BUDGET() declaring a fixed local name, so nesting a budget inside the braces of an enclosing budget shadowed the outer scope object; the macro now uses the existing UNIQUE_ID.

   • One of the 112 was not renamed but removed: in CNPC_AttackHelicopter::Event_Killed the inner declaration re-fetched CSoundEnvelopeController::GetController(), a side-effect-free accessor that returns a reference to a file-static singleton (soundenvelope.cpp). The same object was therefore already in scope and the second declaration was redundant by construction. Every other case either declares a fresh object (a buffer, an RAII guard, a re-initialised local) or re-reads a value that is only incidentally identical, and keeps the rename.

4. C4864 (56 / 2), a dependent template name used without the template keyword in CSOAAttributeReference::operator=.

5. C5055 (21), enumeration constants used in floating point arithmetic, now converted to float explicitly.

6. The single groups: C5033 (register), C4189 (locals that are dead, or referenced by Assert() only in a release build), C4211 (command callbacks that a friend declaration introduces with external linkage now use CON_COMMAND_EXTERN_F), C4005 (INVALID_HANDLE_VALUE is left to the platform headers on Windows and the duplicate ALIGN_VALUE in video_material.cpp is dropped), C4018, C4706, C4554 (parentheses only, the existing evaluation order is kept), C4463 (a 1-bit signed bit-field is made unsigned) and the release-only C4756, where HUGE_VAL becomes std::numeric_limits::infinity(): the same +inf value, but it does not overflow while the LTCG code generator folds the constant.

Not fixed: the five C5205 reports in asw_util_shared.cpp, video_material.cpp and optionssubmultiplayer.cpp. IVguiMatInfo, IVguiMatInfoVar and IDirectSoundBuffer are abstract interfaces implemented outside this solution (the VGUI surface of the prebuilt material system and the DirectSound SDK), and IVguiMatInfo.h explicitly asks the caller to delete the object. Adding a virtual destructor would change the vtable of an interface whose implementation is not rebuilt here, and replacing the delete with a release call would change ownership semantics, so both are worse than the diagnostic.

• Verified with:
• MSBuild src\reactivedrop_vs13.sln /t:Rebuild for Debug|Win32 and Release|Win32 - 0 errors in both, 5 warnings in both, all of them C5205; client.dll, server.dll and missionchooser.dll produced for each configuration.
• Both the Release and the Debug DLLs were then swapped into the game installation and a smoke test was played on one solo map.

[anf3is]

Most changes (all except register keyword?) do not depend on #1115. So probably should omit first commit and move relevant changes to that PR.
Besides, could you please group similar changes together as separate commits? It's pretty hard to review entire blob at once.