How to get the address of a static struct?

[rikki cattermole via Digitalmars-d-learn]

Thread local struct:

```D
module foobar;

struct Foo {
	int x;
}

Foo foo = Foo(8);

void main() {
	import std.stdio;
	writeln(&foo);
}
```

Global struct:

```D
module foobar;

struct Foo {
	int x;
}

__gshared Foo foo = Foo(8);

void main() {
	import std.stdio;
	writeln(&foo);
}
```

Compile time constant:

```D
module foobar;

struct Foo {
	int x;
}

enum FOO = Foo(8);

void main() {
	import std.stdio;
	Foo foo = FOO;
	writeln(&foo);
}
```