for loop not possible for indexexpr with sumtype of array types in coma separated match branch

[ttytm]

Describe the bug

type MySumType = []MyStructA | []MyStructB

struct ParentStruct {
	parent_field string
}

struct MyStructA {
	ParentStruct
}

struct MyStructB {
	ParentStruct
}

fn check(mut t MySumType) {
	match mut t {
		[]MyStructA, []MyStructB {
			// println(t[0].parent_field) // possible now, thanks felipe
			for v in t {
				println(v.parent_field)
			}
		}
	}
}

fn main() {
	s := MyStructA{
		parent_field: 'common'
	}

	mut t := MySumType([s])

	check(mut t)
	assert true
}

Expected Behavior

Looping the array variant is possible.

Current Behavior

sum_arr.v:19:13: error: for in: cannot index `([]MyStructA | []MyStructB)`
   17 |         []MyStructA, []MyStructB {
   18 |             // println(t[0].parent_field) // possible
   19 |             for v in t {
      |                      ^
   20 |                 println(v.parent_field)
   21 |             }
sum_arr.v:20:15: error: `v` does not return a value
   18 |             // println(t[0].parent_field) // possible
   19 |             for v in t {
   20 |                 println(v.parent_field)
      |                           ~~~~~~~~~~~~
   21 |             }
   22 |         }

Reproduction Steps

Possible Solution

No response

Additional Information/Context

No response

V version

0.3.4

Environment details (OS name and version, etc.)

V full version: V 0.3.4 34ac326.ad10282
OS: linux, "Manjaro Linux"
Processor: 16 cpus, 64bit, little endian, 11th Gen Intel(R) Core(TM) i7-11800H @ 2.30GHz

getwd: /home/turiiya/Dev/vlang/v
vexe: /home/turiiya/Dev/vlang/v/v
vexe mtime: 2023-06-24 23:31:07

vroot: OK, value: /home/turiiya/Dev/vlang/v
VMODULES: OK, value: /home/turiiya/.vmodules
VTMP: OK, value: /tmp/v_1000

Git version: git version 2.41.0
Git vroot status: weekly.2023.25-32-gad102829 (3 commit(s) behind V master)
.git/config present: true

CC version: cc (GCC) 13.1.1 20230429
thirdparty/tcc status: thirdparty-linux-amd64 12f392c3