llvm: fix broken native build mode.

_examples/llvm/build.sh

+#! /bin/bash
+
+wa native --target=avr arduino_blink.wa
+wa native array_0.wa
+wa native array_1.wa
+wa native array_2.wa
+wa native bitwise_logic.wa
+wa native compare.wa
+wa native convert_0.wa
+wa native convert_1.wa
+wa native convert_2.wa
+wa native convert_3.wa
+wa native float32.wa
+wa native global_constant.wa
+wa native global_variable_0.wa
+wa native global_variable_1.wa
+wa native heart.wa
+wa native loop_0.wa
+wa native loop_1.wa
+wa native multi_ret.wa
+wa native pointer.wa
+wa native prime.wa
+wa native print_0.wa
+wa native print_1.wa
+wa native print_2.wa
+wa native print_3.wa
+wa native shift.wa
+wa native struct_0.wa
+wa native struct_1.wa
+wa native struct_2.wa
+wa native struct_3.wa
+wa native unconditional_jump.wa
+
+rm -f *.ll *.s

internal/app/opt.go

@@ -44,6 +44,9 @@ func (opt *Option) Config() *config.Config {
 	case "arm64":
 		cfg.WaSizes.MaxAlign = 8
 		cfg.WaSizes.WordSize = 8
+	case "native":
+		cfg.WaSizes.MaxAlign = 8
+		cfg.WaSizes.WordSize = 8
 	default:
 		panic("todo")
 	}

main.go

@@ -304,7 +304,7 @@ func main() {
 				}
 				infile = c.Args().First()
 
-				ctx := app.NewApp(build_Options(c))
+				ctx := app.NewApp(build_Options(c, true))
 				if err := ctx.LLVM(infile, outfile, target, debug); err != nil {
 					fmt.Println(err)
 					os.Exit(1)
@@ -472,6 +472,7 @@ func build_Options(c *cli.Context, isLLVMBackend ...bool) *app.Option {
 	opt.TargetArch = "wasm"
 	if len(isLLVMBackend) > 0 && isLLVMBackend[0] {
 		opt.TargetArch = "native"
+		return opt
 	}
 	switch c.String("target") {
 	case "wa", config.WaOS_Walang: