shader: Fix gcc warnings

src/shader_recompiler/frontend/ir/microinstruction.cpp

@@ -282,7 +282,7 @@ void Inst::ClearArgs() {
         }
         // Reset arguments to null
         // std::memset was measured to be faster on MSVC than std::ranges:fill
-        std::memset(&args, 0, sizeof(args));
+        std::memset(reinterpret_cast<char*>(&args), 0, sizeof(args));
     }
 }
 

src/shader_recompiler/frontend/maxwell/structured_control_flow.cpp

@@ -267,7 +267,7 @@ bool IsIndirectlyRelated(Node goto_stmt, Node label_stmt) {
     return goto_stmt->up != label_stmt->up && !IsDirectlyRelated(goto_stmt, label_stmt);
 }
 
-bool AreSiblings(Node goto_stmt, Node label_stmt) noexcept {
+[[maybe_unused]] bool AreSiblings(Node goto_stmt, Node label_stmt) noexcept {
     Node it{goto_stmt};
     do {
         if (it == label_stmt) {