Possible bug when removing call frame

[tul]

• GopherLua is a Lua5.1 implementation. You should be familiar with Lua programming language. Have you read Lua 5.1 reference manual carefully?
• GopherLua is a Lua5.1 implementation. In Lua, to keep it simple, it is more important to remove functionalities rather than to add functionalities unlike other languages . If you are going to introduce some new cool functionalities into the GopherLua code base and the functionalities can be implemented by existing APIs, It should be implemented as a library.

Please answer the following before submitting your issue:

1. What version of GopherLua are you using? : 46796da
2. What version of Go are you using? : go version go1.10.3 darwin/amd64
3. What operating system and processor architecture are you using? : x86_64
4. What did you do? : N/A
5. What did you expect to see? : N/A
6. What did you see instead? : N/A

In state.go, the Remove method which is used in tail calls has a loop in it that can only execute once, due to the assignment of cs.sp = i which causes the loop to break. I think probably this loop is intended to run through the whole stack.

func (cs *callFrameStack) Remove(sp int) {
	psp := sp - 1
	nsp := sp + 1
	var pre *callFrame
	var next *callFrame
	if psp > 0 {
		pre = &cs.array[psp]
	}
	if nsp < cs.sp {
		next = &cs.array[nsp]
	}
	if next != nil {
		next.Parent = pre
	}
	for i := sp; i+1 < cs.sp; i++ {
		cs.array[i] = cs.array[i+1]
		cs.array[i].Idx = i
		cs.sp = i
	}
	cs.sp++
}

I suspect this is not causing a problem at the moment as this method is only called when making a tail call where it only has to repair 1 stack frame.