defers shouldn't re-run when repanic'ing.

[dgryski]

Looks like the panic in the defer block causes the defer to rerun, when it shouldn't.

~/go/src/github.com/dgryski/bug/repanic $ cat main.go
package main

func main() {
	var rerun int
	defer func() {
		println("defer")
		if r := recover(); r != nil {
			rerun++
			if rerun < 5 {
				panic(r)
			}
		}
	}()

	panic("boom")
}
~/go/src/github.com/dgryski/bug/repanic $ go run main.go
defer
panic: boom [recovered]
	panic: boom

goroutine 1 [running]:
main.main.func1()
	/Users/dgryski/go/src/github.com/dgryski/bug/repanic/main.go:10 +0x6d
panic({0x105ba80, 0x107a8b8})
	/Users/dgryski/go/src/go.googlesource.com/go/src/runtime/panic.go:884 +0x213
main.main()
	/Users/dgryski/go/src/github.com/dgryski/bug/repanic/main.go:15 +0x6c
exit status 2
~/go/src/github.com/dgryski/bug/repanic $ tinygo run main.go
defer
defer
defer
defer
defer