This patch makes changes to the default ABI for RISC-V targets.
Before patch, only integer ABI (ilp32e, ilp32, lp64) can be selected by default (without passing ABIName in MCOptions).
After patch, ilp32f/d and lp64f/d can be selected if F/D extensions are detected.
Tests are updated by adding specifying target-abi if necessary.
I'd put these two declarations the other way round so they match the canonical order; only the uses need to be in "reverse" order to ensure we check from most to least specific.