Problem with Exceptions in Constructor

[Mike Brown]

Hi all,

AddressSanitizer is throwing an access-violation error - I've 
managed to boil it down to this example:

```d
import std.stdio;

class example: Exception {
	this(string msg, string file = __FILE__, size_t line = __LINE__) 
{
		super(msg, file, line);
	}
}

class test {
	this() {		
		throw new example("this is a test");
	}
}

void main() {
	try {
		auto t = new test();
	} catch (example e) {
		writeln(e.msg);
	}
}
```

Compiled with:
ldc2.exe -g -fsanitize='address' .\test.d -of='test.exe'

The error is flagged on the writeln(e.msg). Do I need to do 
something special to pass a string to an exception? dup?

Kind regards,
Mike Brown