shader: run merged geometry stages as mesh shaders

Co-authored-by: Brandon Strong <brandostrong@gmail.com>
Co-authored-by: fxpw <fxpw@outlook.com>
Co-authored-by: shadowbeat070 <70843316+shadowbeat070@users.noreply.github.com>

src/graphics/shader/recompiler/ir/opcodes/ValueOpcodes.cpp

@@ -90,6 +90,7 @@ bool HasSideEffects(ValueOpcode opcode) {
 		case ValueOpcode::Reference:
 		case ValueOpcode::ReferenceU32:
 		case ValueOpcode::SetAttribute:
+		case ValueOpcode::MeshAllocate:
 		case ValueOpcode::Barrier: return true;
 		default: return false;
 	}