Switch exhaustiveness not working for typeof any and typeof unknown

[cherryblossom000]

TypeScript Version: 3.9.5, 4.0.0-dev.20200630

Search Terms: switch narrowing typeof any unknown

Code
Making x unknown also gives the same results.

const works = (x: any): number => {
  const type = typeof x
  switch (type) {
    case 'string': return 0
    case 'number': return 0
    case 'bigint': return 0
    case 'boolean': return 0
    case 'symbol': return 0
    case 'undefined': return 0
    case 'object': return 0
    case 'function': return 0
  }
}

const alsoWorks = (x: any): number => {
  switch (typeof x as 'string' | 'number' | 'bigint' | 'boolean' | 'symbol' | 'undefined' | 'object' | 'function') {
    case 'string': return 0
    case 'number': return 0
    case 'bigint': return 0
    case 'boolean': return 0
    case 'symbol': return 0
    case 'undefined': return 0
    case 'object': return 0
    case 'function': return 0
  }
}

const doesntWork = (x: any): number => {
  //                   ~~~
  // TS 2366: Function lacks ending return statement and return type does not include 'undefined'.
  switch (typeof x) {
    case 'string': return 0
    case 'number': return 0
    case 'bigint': return 0
    case 'boolean': return 0
    case 'symbol': return 0
    case 'undefined': return 0
    case 'object': return 0
    case 'function': return 0
  }
}

Expected behavior: No error in doesntWork as the switch is exhaustive. This should be the same as works (using a variable) and alsoWorks (using a type assertion).

Actual behavior: Error TS 2366: Function lacks ending return statement and return type does not include 'undefined'. with strictNullChecks.

Playground Link

Related Issues: #34661, #38136, #27180