miscompilation of a break after a range-loop

[eliasnaur]

This program runs forever on TinyGo:

package main

import (
	"fmt"
	"iter"
)

func splitSeq() iter.Seq[string] {
	return func(yield func(string) bool) {
	}
}

func main() {
	fmt.Println("start")
	defer fmt.Println("finish")
	for {
		for range splitSeq() {
		}
		break
	}
}

To reproduce:

$ go run stub2.go
start
finish
$ tinygo version
tinygo version 0.38.0-dev-612a38e3 darwin/arm64 (using go version go1.24.2 and LLVM version 18.1.8)
$ tinygo run stub2.go
start
<hang>

Adding an explicit break target fixes the hang:

package main

import (
	"fmt"
	"iter"
)

func splitSeq() iter.Seq[string] {
	return func(yield func(string) bool) {
	}
}

func main() {
	fmt.Println("start")
	defer fmt.Println("finish")
loop:
	for {
		for range splitSeq() {
		}
		break loop
	}
}

$ tinygo run stub3.go
start
finish