C code generation error with generic event waiters in discord.v library on V 0.5.1

[GurlaganSingh]

Describe the bug

Running ./v -g -o vdbg cmd/v && ./vdbg 'main.v' && 'main' on main.v produced a compiler error.

Reproduction Steps

./v -g -o vdbg cmd/v && ./vdbg 'main.v' && 'main'

module main

import discord
import os

fn main() {
	mut bot := discord.bot(os.getenv_opt('DISCORD_BOT_TOKEN') or {
		eprintln('No token specified')
		exit(1)
	}, intents: .message_content | .guild_messages)
	bot.events.on_ready.listen(fn (event discord.ReadyEvent) ! {
		println('Logged as ${event.user.username}! Bot has ${event.guilds.len} guilds')
	})
	bot.events.on_message_create.listen(fn (event discord.MessageCreateEvent) ! {
		if event.message.content != '!ping' {
			return
		}
		event.creator.rest.create_message(event.message.channel_id, content: 'Pong')!
	})
	bot.launch()!
}

### Expected Behavior

**V version:** V 0.5.1
**OS:** Void Linux (glibc)

**What did I do?**
Tried to compile a Discord bot using the `discord.v` library (https://github.com/DarpHome/discord.v) after fixing deprecated `json2.raw_decode()` calls to `json2.decode[json2.Any]()`.

**What did I expect to see?**
Successful compilation and a working Discord bot.

**What did I see instead?**
C compilation error from both tcc and clang backends. The V compiler generates invalid C code when compiling generic event waiters in the discord library.

Steps to reproduce:

1. v install --git https://github.com/DarpHome/discord.v
2. Fix src/ directory issue: mv ~/.vmodules/discord/src/*.v ~/.vmodules/discord/ && rmdir ~/.vmodules/discord/src
3. Fix deprecated json2.raw_decode() → json2.decode[json2.Any]() across all .v files
4. Create minimal bot:

module main

import discord

fn main() {
    mut bot := discord.new_bot(discord.BotConfig{
        token: 'YOUR_TOKEN'
    })!
    bot.run()!
}

### Current Behavior

```bash
/home/lagan/.vmodules/discord/cache.v:191:15: warning: accessing map value that contain pointers requires an `or {}` block outside `unsafe`
  189 |     }
  190 |     mut m2 := unsafe { mut m1[id1] }
  191 |     if id2 !in m1[id1] {
      |                  ~~~~~
  192 |         if sz := max_size2 {
  193 |             if m2.len >= sz {
================== C compilation error (from tcc): ==============
cc: thirdparty/tcc/lib/tcc/include/stdarg.h:8: warning: va_end redefined
cc: /tmp/v_1000/main.01KS538PGMYDWK92AHKGT73F59.tmp.c:94397: error: '{' expected (got ";")
...
cc: /tmp/v_1000/main.01KS538PGMYDWK92AHKGT73F59.tmp.c:94397: error: '{' expected (got ";")
(note: the original output was 17 lines long; it was truncated to its first 2 lines + the last line)
=================================================================
Try passing `-g` when compiling, to see a .v file:line information, that correlates more with the C error.
(Alternatively, pass `-show-c-output`, to print the full C error message).
builder error: 
==================
C error found while compiling generated C code.
This can be caused by invalid C interop code, C compiler flags, or a V compiler bug.
If your code is pure V and this still happens, please report it using `v bug file.v`,
or goto https://github.com/vlang/v/issues/new/choose .
You can also use #help on Discord: https://discord.gg/vlang .

Possible Solution

No response

Additional Information/Context

Generated by v bug from main.v.

V version

V 0.5.1 b32f9ab

Environment details (OS name and version, etc.)

|V full version      |V 0.5.1 b32f9abce86304dd09d098f5b58ad89051ab1917
|:-------------------|:-------------------
|OS                  |linux, "Void Linux"
|Processor           |2 cpus, 64bit, little endian, Intel(R) Celeron(R) N4500 @ 1.10GHz
|Memory              |1.15GB/7.61GB
|                    |
|V executable        |/home/lagan/v/v
|V last modified time|2026-05-20 17:09:13
|                    |
|V home dir          |OK, value: /home/lagan/v
|VMODULES            |OK, value: /home/lagan/.vmodules
|VTMP                |OK, value: /tmp/v_1000
|Current working dir |OK, value: /home/lagan/Documents/vbot
|                    |
|Git version         |git version 2.54.0
|V git status        |b32f9abc
|.git/config present |true
|                    |
|cc version          |clang version 21.1.7
|gcc version         |gcc (GCC) 14.2.1 20250405
|clang version       |clang version 21.1.7
|tcc version         |tcc version 0.9.28rc 2025-02-13 HEAD@f8bd136d (x86_64 Linux)
|tcc git status      |thirdparty-linux-amd64 696c1d84
|emcc version        |N/A
|glibc version       |ldd (GNU libc) 2.41

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