shader: implement RDNA2 scalar quad-mask reduction

src/graphics/shader/recompiler/frontend/decode/ScalarAluOps.cpp

@@ -52,6 +52,7 @@ constexpr OpcodeMap SOP1_OPCODE_LIST[] = {
     {0x20u, Opcode::S_SETPC_B64},
     {0x24u, Opcode::S_AND_SAVEEXEC_B64},
     {0x28u, Opcode::S_ORN2_SAVEEXEC_B64},
+    {0x2du, Opcode::S_QUADMASK_B64},
     {0x34u, Opcode::S_ABS_I32},
     {0x37u, Opcode::S_ANDN1_SAVEEXEC_B64},
     {0x3bu, Opcode::S_BITREPLICATE_B64_B32},

src/graphics/shader/recompiler/frontend/decode/ShaderDecoder.cpp

@@ -498,6 +498,7 @@ std::string InstructionToString(const Instruction& inst) {
 		case Opcode::S_FF1_I32_B64:
 		case Opcode::S_NOT_B64:
 		case Opcode::S_WQM_B64:
+		case Opcode::S_QUADMASK_B64:
 		case Opcode::S_AND_SAVEEXEC_B32:
 		case Opcode::S_ANDN1_SAVEEXEC_B32:
 		case Opcode::S_AND_SAVEEXEC_B64:

src/graphics/shader/recompiler/frontend/decode/ShaderDecoder.h

@@ -47,6 +47,7 @@ enum class Opcode {
 	S_FF1_I32_B64,
 	S_FLBIT_I32_B64,
 	S_BITREPLICATE_B64_B32,
+	S_QUADMASK_B64,
 	S_GETPC_B64,
 	S_SETPC_B64,
 	S_AND_SAVEEXEC_B32,