shader_recompiler: translate Switch 2 task and mesh programs

Mario Kart World draws some of its geometry with NVN task and mesh programs
(the task program culls and writes the mesh workgroup count and a payload
to its stage buffer; each mesh workgroup reads it back and writes vertices
and primitives). Add Task and Mesh stages and translate them for
VK_EXT_mesh_shader:

- the ISBE pseudo instruction from the lowering becomes reads and writes
  of an emulated stage buffer: the task's output region is the task
  payload, the mesh output regions live in workgroup memory
- every EXIT of these stages jumps to one final return, so all
  invocations reach the epilogue: a barrier, then OpEmitMeshTasksEXT, or
  OpSetMeshOutputsEXT and a copy of the 32-element vertex and primitive
  groups (lines named by the mesh header's and the pass-through geometry
  header's output maps) to arrayed and per-primitive outputs
- Sirit lacks the two mesh instructions: they are emitted as OpStore
  markers and replaced after assembly
- fragment inputs a mesh program writes per primitive get PerPrimitiveEXT

The captured task and mesh programs of the title translate to SPIR-V that
spirv-val accepts.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/shader_recompiler/backend/glasm/glasm_emit_context.cpp b/src/shader_recompiler/backend/glasm/glasm_emit_context.cpp
index 333a91cc58..02b6992b52 100644
--- a/src/shader_recompiler/backend/glasm/glasm_emit_context.cpp
+++ b/src/shader_recompiler/backend/glasm/glasm_emit_context.cpp
@@ -80,6 +80,9 @@ EmitContext::EmitContext(IR::Program& program, Bindings& bindings, const Profile
     case Stage::Compute:
         stage_name = "invocation";
         break;
+    case Stage::Task:
+    case Stage::Mesh:
+        throw NotImplementedException("GLASM task and mesh programs");
     }
     const std::string_view attr_stage{stage == Stage::Fragment ? "fragment" : "vertex"};
     const VaryingState loads{info.loads.mask | info.passthrough.mask};