parser: fix mutiple imports at one line

[kbkpbot]

Fix issue #24240

[huly-for-github]

Connected to Huly®: V_0.6-22623

[JalonSolov]

I'm not sure this is the correct fix.

Because V treats whitespace as optional,

import import import os

should be treated the same as

import import
import os

The actual problem is that the import statement could be followed by other things, as in

import import as im

So what probably should be happening is that as soon as the 3rd token is not as, it should treat it as a completely separate statement, not as an error.

[kbkpbot]

I do some tests, seems work fine.

import math import import as im import os import kitty as k import ss

after v fmt

import math
import import as im
import os
import kitty as k
import ss

some error cases:

import import as

$ v fmt ff.v
ff.v:2:1: error: unexpected eof, expecting name
    1 | import import as

Internal vfmt error while formatting file: ff.v.

import import import

$ v fmt ff.v
ff.v:2:1: error: unexpected eof, expecting name
    1 | import import import

Internal vfmt error while formatting file: ff.v.

import import import as td

$ v fmt ff.v
ff.v:1:25: error: cannot import multiple modules at a time
    1 | import import import as td
      |                         ~~

Internal vfmt error while formatting file: ff.v.