video_core: Implement basic compute shaders and more instructions

src/shader_recompiler/frontend/control_flow_graph.h

@@ -21,6 +21,7 @@ using Hook =
 enum class EndClass {
     Branch, ///< Block ends with a (un)conditional branch.
     Exit,   ///< Block ends with an exit instruction.
+    Kill,   ///< Block ends with a discard instruction.
 };
 
 /// A block represents a linear range of instructions.