Don't store line pragmas in release builds

Some low hanging fruit for memory usage, the compiler currently produces and stores line pragma information as part of a `RazorCodeDocument`, but the information is only used in tests. Even just simply putting `#if DEBUG` around all of it would be a small, but easy, win.

Locate RazorCodeDocument and its line pragma storage, then trace the tests that consume that information and compare Debug versus release builds. Done means release builds no longer retain the data while the relevant tests still pass.

Written by the indexing model from the issue text.