LDC - DMD sync strategy

[Trass3r via digitalmars-d-ldc]

> E.g.: there is only 1 test failure left in the merge-2.064 
> branch: a missing symbol in std.uni unittest. The merge-2.065 
> branch has some more problems in phobos unit tests - because I 
> did not fixed the changes.

Tested the x64 MSVC combination and the 2.065 branch crashes when 
building the runtime. 2.064 has less problems but now I enabled 
llvm assertions and it hits 2 of them. Do you build with 
assertions?