ARM: deduplicate hard-float detection code. NFC.

ARMSubtarget had a copy/pasted block to determine whether the target was
hard-float, but it just delegated to triple features anyway so it's better at
the TargetMachine level.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337384 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed