cgen error on sizeof call with matching array type of sumtype

[gechandesu]

V version: V 0.4.9 cfeb1bb, press to see full `v doctor` output

V full version	V 0.4.9 5ec9bb5.cfeb1bb
OS	linux, Linux version 6.6.8-arch1-1 (linux@archlinux) (gcc (GCC) 13.2.1 20230801, GNU ld (GNU Binutils) 2.41.0) #1 SMP PREEMPT_DYNAMIC Thu, 21 Dec 2023 19:01:01 +0000
Processor	16 cpus, 64bit, little endian, 12th Gen Intel(R) Core(TM) i5-1240P
Memory	0.71GB/15.35GB
V executable	/home/ge/.vlang/v
V last modified time	2025-02-20 07:30:30
V home dir	OK, value: /home/ge/.vlang
VMODULES	OK, value: /home/ge/.vmodules
VTMP	OK, value: /tmp/v_1000
Current working dir	OK, value: /home/ge/Code/v/zmq
Git version	git version 2.48.1
V git status	weekly.2025.08-15-gcfeb1bb5
.git/config present	true
cc version	cc (GCC) 14.2.1 20250207
gcc version	gcc (GCC) 14.2.1 20250207
clang version	clang version 19.1.7
tcc version	tcc version 0.9.28rc 2024-07-31 HEAD@1cee0908 (x86_64 Linux)
tcc git status	thirdparty-linux-amd64 0134e9b9
emcc version	N/A
glibc version	ldd (GNU libc) 2.41

What did you do?
./v -g -o vdbg cmd/v && ./vdbg /tmp/match_err.vv && /tmp/match_err

module main

type Value = int | i64 | u64 | string | []u8

fn main() {
	val := Value(0)
	match val {
		int, i64, u64, []u8 {
			s := sizeof(val)
			println('Value is number or byte array, size=${s}')
		}
		string {
			println('Value is string')
		}
	}
}

What did you see?

================== C compilation error (from tcc): ==============
cc: /tmp/v_1000/match_err.01JMH483Y6AGNJT4YA1Z2M4M1D.tmp.c:5425: error: 'main__int___main__i64___main__u64___main__' undeclared
=================================================================
(You can pass `-cg`, or `-show-c-output` as well, to print all the C error messages).
builder error: 
==================
C error found. It should never happen, when compiling pure V code.
This is a V compiler bug, 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 .

With -show-c-output:

======== Output of the C Compiler (/home/ge/.vlang/thirdparty/tcc/tcc.exe) ========
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5425: error: 'main__int___main__i64___main__u64___main__' undeclared
===================================================================================
======== Output of the C Compiler (cc) ========
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c: In function ‘main__main’:
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5425:32: error: ‘main__int___main__i64___main__u64___main__’ undeclared (first use in this function)
 5425 |                 u32 s = sizeof(main__int___main__i64___main__u64___main__[]u8);
      |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5425:32: note: each undeclared identifier is reported only once for each function it appears in
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5425:75: error: expected expression before ‘]’ token
 5425 |                 u32 s = sizeof(main__int___main__i64___main__u64___main__[]u8);
      |                                                                           ^
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5429:75: error: expected expression before ‘]’ token
 5429 |                 u32 s = sizeof(main__int___main__i64___main__u64___main__[]u8);
      |                                                                           ^
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5433:75: error: expected expression before ‘]’ token
 5433 |                 u32 s = sizeof(main__int___main__i64___main__u64___main__[]u8);
      |                                                                           ^
/tmp/v_1000/match_err.01JMH49E94N1X6Z3X2KDF76W9J.tmp.c:5437:75: error: expected expression before ‘]’ token
 5437 |                 u32 s = sizeof(main__int___main__i64___main__u64___main__[]u8);
      |                                                                           ^
===============================================

What did you expect to see?

No C errors

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[huly-for-github]

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