about JsDiagGetFunctionPosition. This maybe a bug.

```
auto str = "function test(){}"

auto fn = JsRun str
JsValueRef info = JS_INVALID_REFERENCE
auto result = JsDiagGetFunctionPosition fn, &info
```
is ok.

```
auto str = "function test(){
console.log("");
console.log("");
console.log("");
console.log("");
... repeat 200 ...// need more in your computer maybe
console.log("");
}

auto fn = JsRun str
JsValueRef info = JS_INVALID_REFERENCE
auto result = JsDiagGetFunctionPosition fn, &info
```

assert at FunctionBody:1757 of ChakraCore Release 1.5.2
Assert(IsFunctionBody());

0x00007FFE610D72F8 (ChakraCore.dll) test.exe 0xC0000420: Assertion Failure。