[PATCH] Enable all targets on Windows (MSVC)

[Tim Northover]

>> Generally, looks reasonable to me. Do you have any numbers of hand,
>> though? E.g. differences in build times?
>
> A quick set of tests building check-all LLVM+Clang (Debug, MSVC 2010
> on the Windows side) gives:
>
> Windows:
> X86: 50 minutes
> all: 61 minutes
> = 22% longer
>
> Linux:
> X86: 38 minutes
> all: 44 minutes
> = 19% longer

Ping? I think those numbers are reasonable: the extra work isn't that
different between Linux and Windows and there's still the option of
disabling targets if build time really is important.

Tim.