[PATCH] D27042: lld: Default image base address to 0x400000

[Rafael Espíndola via llvm-commits]

> OK, good point: that will certainly make it easier to update and
> review a subset of tests. However, I will want to update arm64 very
> shortly thereafter.

Sure, no objections to that, it is just nicer to have this done in
independent patches and with each constructor with a comment on why a
given value is used.

Cheers,
Rafael