Struct with default ctor (Was: [dmd-beta] dmd 2.064 beta take 2)

[Igor Stepanov]

When programmer see constructor, he think that it will be 
evaluated each time when he create a new object.
This code will seem obvious for any C++ coder.
And this coder will be deceived.

If we'll add default constructor to structs, we'll must safe of 
illusion, that constructor is called any time when new object 
have been created. And reject all cases when we can't provide 
this illusion.