Describe the bug

There are a subtle differnce between how checks for internface and sum type is performed based on how the variable is declared.

module main

interface ISomeStruct {
	something string
}

struct SomeStruct {
	something string
}


fn test(s &ISomeStruct) {
	println(s)	// shows &ISomeStruct(0x0) for working example , then &nil for failing example
	if s is SomeStruct {
		println("match")
	} else {
		println("no match")
	}
}

fn main() {
	y:=unsafe { nil }
	test(y)	// work
	test(unsafe { nil }) // does not work signal 11: segmentation fault
}

Reproduction Steps

Run code in description.

Expected Behavior

Same behaviour, nog sgment fault.

Current Behavior

v run bug4.v
&ISomeStruct(0x0)
no match
&nil
signal 11: segmentation fault
0 libsystem_platform.dylib 0x00007ff81d2155ed _sigtramp + 29
1 dyld 0x00007ff81ceb5ff4 ZN3lsl19PersistentAllocator12reserveRangeERNS_5BTreeINS_13MemoryManager6BufferENS0_17RegionSizeCompareELb0EE14const_iteratorES3 + 666
2 bug4 0x0000000101aa8dea main__main + 74
3 bug4 0x0000000101aa8ff7 main + 71
4 dyld 0x00007ff81ce8d418 start + 1896

Possible Solution

No response

Additional Information/Context

This is destilled from v-analyze issue #162 that happens in the v-analyze

V version

0.4.10

Environment details (OS name and version, etc.)