C error. thread from fn struct variable

[dnkdev]

Describe the bug

So this works:

fn do() {
	println('hello')
}

f := do
p := spawn f()
p.wait()

But this doesn't work:
Code: https://vosca.dev/p/0733bbb6d7

struct S1 {
mut:
	func fn ()
}

fn do() {
	println('hello')
}

mut s := S1{}

s.func = do
p := spawn s.func()
p.wait()

Expected Behavior

no c error

Current Behavior

Output:

/tmp/v_60000/code.11089087381689797842.tmp.c:2142: error: field not found: fn
builder error: 
==================
C error. This should never happen.

This is a compiler bug, please report it using `v bug file.v`.

https://github.com/vlang/v/issues/new/choose

You can also use #help on Discord: https://discord.gg/vlang

Exited with error status 1

Reproduction Steps

.

Possible Solution

No response

Additional Information/Context

No response

V version

0.4.0

Environment details (OS name and version, etc.)

V full version: V 0.4.0 fc4c431.a9a94cf
OS: linux, Ubuntu 22.04.2 LTS
Processor: 2 cpus, 64bit, little endian, Intel(R) Xeon(R) CPU E5-2670 v2 @ 2.50GHz

getwd: /home/pmakhnev/playground
vexe: /home/pmakhnev/v/v
vexe mtime: 2023-07-13 18:00:08

vroot: OK, value: /home/pmakhnev/v
VMODULES: OK, value: /root/.vmodules
VTMP: OK, value: /tmp/v_0

Git version: git version 2.34.1
Git vroot status: weekly.2023.27-63-ga9a94cfd (5 commit(s) behind V master)
.git/config present: true

CC version: cc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
thirdparty/tcc status: thirdparty-linux-amd64 12f392c3