fix issue #1124

I fix this issue by adding a context to determine if the current expression is under the class field. if is true, then it is legal to use an in operator with privatename token. if is false. parse would throw an error.

And I find a problem is that terser allow parse function to accept private field even out of class field, which should be a syntax error. so I add a condition to subscripts function to determine if the current subscript is under class feild. if is true, parse would parse it correctly, if is false it would throw an error.

To pass the test, I delete one test from /compress/class-properity which allows parse function to accept private fields even out of class field, which should be a syntax error.

I also add a condition to binary expression, because even class field can use in operation with privatename, other expressions like add can’t use privatename without subscript. for example :

// in class field
 #p in this // pass
 this.#p + 10 // pass
 input.#p + 10 // pass, input can be a param
 #p + 10 // error