shader: preserve untouched half in VOP1 B16 writes (#370)

shader: preserve native 16-bit destinations

Co-authored-by: nmzik <Nmzik@mail.ru>

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

@@ -632,6 +632,7 @@ struct Operand {
 	uint32_t dpp_ctrl           = 0;
 	uint32_t dpp_row_mask       = 0xf;
 	uint32_t dpp_bank_mask      = 0xf;
+	bool     explicit_sdwa_dst  = false;
 	bool     sdwa_sext          = false;
 	bool     dpp_fetch_inactive = false;
 	bool     dpp_bound_ctrl     = false;