ASSERTION failure in ChakraCore/lib/Runtime/Language/CacheOperators.cpp, line 178

The debug build of Chakacore crashes.
PoC:
```
function testReconfigureAsAccessorProperty(f) {
var length = 2;
Object.defineProperty(f, 'length', {
get: function () {
return length;
},
set: function (v) {
length = v;
}
});
}
(function testSetOnInstance() {
function f() {}
delete f.length;
testReconfigureAsAccessorProperty(f);
Object.defineProperty(Function.prototype, 'length', {
writable: true
});
f.length = 123;
print(f.length); // It should print 123; but print 0
})();

```
Version= `e79d68a` on master branch
OS=Ubuntu 16.04.6
Arch=x86_64