Special compilation mode

[Robert Fraser]

Arlen Albert Keshabyan wrote:
>    It would be very handy to introduce a special compilation mode in the D compiler that would build a special report file instead of a binary object file upon a source code file compilation. It’s supposed to contain special information on types, variable and class names, errors, warnings, optimization notes and other useful information that would help an IDE (or any other frontends) to help programmers in a code completion and in other useful things. It’s supposed to run fast in a background like Eclipse does that to java source files.
> 
>    Does Walter consider that worth of his attention to bother about?

The problem is, it's difficult to determine exactly what should be in 
such a file. If you need complete semantic information, it would be a 
lot easier to just embed the DMD front-end or dil or something.