Gate clip/cull distance builtins on Vulkan feature support

[zeyadadev]

Summary

• Skip ClipDistance/CullDistance SPIR-V capability and builtin emission when the Vulkan device doesn't report shaderClipDistance/shaderCullDistance support
• Covers both DXBC (D3D10/11) and DXSO/D3D9 fixed-function shader pipelines
• No behavioral change on desktop GPUs (NVIDIA, AMD, Intel) where these features are always enabled

Motivation

Some mobile GPUs (e.g. Mali) don't expose shaderClipDistance/shaderCullDistance. Previously DXVK would unconditionally emit these builtins, producing invalid SPIR-V that causes crashes or rendering failures on such hardware

Changes

• dxbc: Guard CapabilityClipDistance/CapabilityCullDistance in VS, HS, DS, GS init; skip emitDclClipCullDistanceArray when feature is off
• dxso: Guard CapabilityClipDistance and emitVsClipping; move invariantPosition decoration after oPos.id validation
• d3d9 fixed-function: Add enableClipDistance to D3D9FixedFunctionOptions, gate clipping emission

[pythonlover02]

thx for the work mate, everything looks good on the code, so merging :)