ASSERTION Failure: (opndConstructor->m_sym->m_isSingleDef) in ChakraCore/lib/Backend/IRBuilder.cpp, line 2394

### commit
41ad58a9eebf8d52a83424c8fccfaacdb14105ec

### Build platform
Ubuntu 20.04

### Build steps

```
./build.sh --debug
```

### poc

```
function foo(o) {
switch (o.f) {
case 1:
return 1;
case 2:
return class Baz{};
default:
return 0;
}
}

function bar() {
for (var i = 0; i < 64; ++i)
x += foo( { f: 5 } );
}

var x = bar();

```

### assert log

```
ASSERTION 2399095: (ChakraCore/lib/Backend/IRBuilder.cpp, line 2394) opndConstructor->m_sym->m_isSingleDef
Failure: (opndConstructor->m_sym->m_isSingleDef)
Illegal instruction
```