checker: Variadic option type ...?T incorrectly wraps the implicit array in an outer Option type

[skandhas]

Describe the bug

There is a bug in the type checker when handling a combination of variadic arguments and option types (...?T).

Instead of treating the argument internally as a plain array of options ([]?T), the compiler incorrectly wraps the entire implicit array into an outer Option type, resulting in ?[]?T. This causes a compilation failure when passing it to a function expecting []?T.

Reproduction Steps

module main

type Job = fn ()

fn compact(values []?Job) {
	_ := values
}

fn combine(values ...?Job) {
	compact(values)
}

fn main() {
}

Expected Behavior

The code should compile successfully and values ...?Job should be checked inside the function as a plain array []?Job, not an optional array ?[]?Job

Current Behavior

option.v:10:10: error: cannot use `?[]?fn ()` as `[]?fn ()`, it must be unwrapped first in argument 1 to `compact`
    8 |
    9 | fn combine(values ...?Job) {
   10 |     compact(values)
      |             ~~~~~~
   11 | }
   12 |

Possible Solution

No response

Additional Information/Context

No response

V version

V 0.5.2 a5a89d5

Environment details (OS name and version, etc.)

|V full version      |V 0.5.2 09062b4577f57aa3ca57adb528d751824d8f51a8.a5a89d5
|:-------------------|:-------------------
|OS                  |windows, Microsoft Windows 11 Home 26200 64-bit
|Processor           |16 cpus, 64bit, little endian, 12th Gen Intel(R) Core(TM) i5-1240P
|Memory              |17.6GB/31.58GB
|                    |
|V executable        |D:\sdks\v\v.exe
|V last modified time|2026-08-03 10:50:00
|                    |
|V home dir          |OK, value: D:\sdks\v
|VMODULES            |OK, value: C:\Users\skand\.vmodules
|VTMP                |OK, value: C:\Users\skand\AppData\Local\Temp\v_0
|Current working dir |OK, value: D:\workd\vtools\bug\2
|                    |
|Git version         |git version 2.51.1
|V git status        |a5a89d56
|.git/config present |true
|                    |
|cc version          |cc (Rev3, Built by MSYS2 project) 16.1.0
|gcc version         |gcc (Rev3, Built by MSYS2 project) 16.1.0
|clang version       |clang version 22.1.7 (https://github.com/msys2/MINGW-packages b8f306ad57e0c8f3f15aed0dc809d7e3e8e2eee9)
|msvc version        |N/A
|tcc version         |tcc version 0.9.28rc 2026-07-14_HEAD@d9d02c56* (x86_64 Windows)
|tcc git status      |thirdparty-windows-amd64 f7c7199b-dirty
|emcc version        |N/A
|glibc version       |ldd (cygwin) 3.6.9

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