Support TypeScript 4.3 get/set type members - #13089

Instead of using lookahead (which is expensive) in tsParseMethodSignatureKind, can we:

• Call this.parsePropertyName
• If not computed, not private, does not have type parameters, and the identifier name is get or set:
  • If tsNextTokenCanFollowModifier, then we are parsing an accessor and we call this.parsePropertyName again
  • Otherwise, it's a method/property named get or set
• Otherwise, it's a method/property

Yeah we parse class accessors using the same strategy mentioned above.

What the AST babel should return for below code?

interface Foo {
    set foo;
}

In current behaviour, two properties named set and foo are returned (with recoverable error Missing semicolon). If we should keep it, we should detect if the property is a method signature after first this.parsePropertyName call. But then the token is the name of the property, so I don't know how to do that without lookahead...

It's ok to throw "Expected (":

• It's what we already do for

  class Foo {
    set foo
  }

• It's more likely that someone didn't finish writing a setter, than putting two properties on the same line without ; and that the name of the first one was exactly set.