D1 and Phobos Fixes

[Walter Bright]

Spacen Jasset wrote:
> This goes for the compiler too, but presumably a lot of the the code is 
> shared and it isn't so easy.

Many compiler patches get posted to bugzilla. About half of them are 
correct, the other half aren't (often fixing the symptom rather than the 
cause of the problem).

Essentially, the compiler is fairly complicated and not well commented; 
I want to review any changes before they're committed. Otherwise I'll 
lose track of how it works and how it's supposed to work.