Add an option to ignore unread ("evolving") anys

[danvk]

Fixes(if relevant): #28

Checks

• [x] Contains Only One Commit(git reset then git commit)
• [x] Build Success(npm run build)
• [ ] Lint Success(npm run lint to check, npm run fix to fix): there were lint failures but not related to my code
• [x] File Integrity(git add -A or add rules at .gitignore file)
• [ ] Add Test(if relevant, npm run test to check): I can't find any tests in this repo, please advise!
• [ ] Add Demo(if relevant): I'd love to add one, please let me know how

Test/demo file:

$ cat test.ts
let val;  // any
if (Math.random() < 0.5) {
  val = /hello/;  // any
  val  // RegExp
} else {
  val = 12;  // any
  val  // number
}
val  // number | RegExp

Without the new flag: lines 1, 3 and 6 are flagged as anys With the new flag: no errors are flagged

Anecdotally, here's the diff for my project:

54890 / 55533 98.84% Before
55110 / 55533 99.23% After

So this removed 220/643 of the issues flagged by type-coverage. I skimmed through many of these and they seemed fine.

This is a long-standing pattern that has been allowed in TS since version 2.1.

[danvk]

@plantain-00 let me know if you're comfortable with this change and how I should test it. I'm very open to suggestions on names for this flag.

[plantain-00]

released in v2.14.0

[danvk]

Amazing, thanks @plantain-00!!