Reactor: Add address-of operator on reference types.

Reactor: Add address-of operator on reference types.

Allows expressions like:

Array<Float4> arr;
Pointer<Float4> ptr = &arr[0];

Bug: b/126330097
Change-Id: I4ad95b46cfa1332eded0424ba4aeb7fe8642b71a
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/25709
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>