code coverage and module constructors

[BCS]

	If two modules mutually import each other, you can't use code coverage 
on both of them. This is (I think) because the code coverage is 
implemented with some sort of module constructor and generate a loop 
(static this in mod-a must be run before the static this in mod-b which 
must be run before the static this in mod-a ...).

	However this is bunk, -cov for one module shouldn't have any 
dependencies on any other module. D already has one case where a module 
constructor like thing is use that doesn't care about circular imports, 
unittests. Why then isn't the cov startup run the same way?