try / catch not working with 'normal errors' like null pointer exceptions

[jwunderl]

Describe the bug

It looks like try / catches only work with explicit 'throws', and not normal errors (too big allocation, out of memory, null pointer exceptions)

To Reproduce
Steps to reproduce the behavior:

1. Go to https://makecode.com/_7J3PqJbPUDvU
2. run game (hardware / sim have same behavior)
3. See it works; comment out line 3 (throw "error!")
4. run game
5. See error

Expected behavior

Ideally it'd be nice for catch to support these, but if not we should probably add it back in as a caveat in https://makecode.com/language

Additional context

let mySprite: Sprite;
try {
    // throw "error!"
    mySprite.setPosition(1, 2)
} catch (e) {
    mySprite = sprites.create(img`
        . . . . . . . . . . . . . . . .
        . . . . . . . . . . b 5 b . . .
        . . . . . . . . . b 5 b . . . .
        . . . . . . b b b b b b . . . .
        . . . . . b b 5 5 5 5 5 b . . .
        . b b b b b 5 5 5 5 5 5 5 b . .
        . b d 5 b 5 5 5 5 5 5 5 5 b . .
        . . b 5 5 b 5 d 1 f 5 d 4 f . .
        . . b d 5 5 b 1 f f 5 4 4 c . .
        b b d b 5 5 5 d f b 4 4 4 4 4 b
        b d d c d 5 5 b 5 4 4 4 4 4 b .
        c d d d c c b 5 5 5 5 5 5 5 b .
        c b d d d d d 5 5 5 5 5 5 5 b .
        . c d d d d d d 5 5 5 5 5 d b .
        . . c b d d d d d 5 5 5 b b . .
        . . . c c c c c c c c b b . . .
    `)
}