This is a mostly NFC change cleaning up and clarifying components of the
in-tree CORE-V (xcv*) extensions following discussions on the remaining
extensions.
This makes the following changes to the xcbitmanip and xcvmac support:
- Add missing extensions from RISCVISAInfo, such that they can be supported in clang's -march option.
- Clarify the extension version number is 1.0.0 in documentation.
- Clarify the extensions are by OpenHW Group, and the capitilization of the CORE-V extension family.
- Add CORE-V to extension name in RISCVFeatures, both to be consistent with other vendors, and also better distinguish e.g. CORE-V bit manipulation vs RISC-V's standard Zb extensions.