shader: resolve workgroup-selected descriptor prefixes from dispatch arguments

Co-authored-by: fxpw <fxpw@outlook.com>

src/graphics/shader/recompiler/ir/passes/SrtWalker.h

@@ -19,6 +19,7 @@ struct SrtRuntime {
 	void*                     userdata                   = nullptr;
 	SrtMemoryReader           read_specialization_memory = nullptr;
 	std::span<const uint32_t> workgroup_counts;
+	uint64_t                  indirect_args_address = 0;
 };
 
 class SrtReadCapture {