[PATCH] Set properties of f128 type

[Tim Northover]

> This patch sets properties of f128 type in
> TargetLoweringBase::computeRegisterProperties. This is needed to enable
> soft-float on architectures which have support for f128. mips64 is an
> example of such an architecture. aarch64 also supports f128, but it doesn't
> need this because it doesn't have a soft-float ABI.

It looks clearly in line with the surrounding code to me, but is there
some kind of test you could write for MIPS that would demonstrate it?
We don't do much merging on trunk, but it could help avoid an obvious
blunder in some future refactoring effort.

Cheers.

Tim.