This patch set introduce new set of architecture extension test macros which is accept on riscv-c-api-doc[1] recently.
The motivation of this scheme is have an unify naming scheme for extension macro and add the capability to checking version. V2 Changes: - Fix MacOS build issue. - Create new header file: riscv-subset.h [1] https://github.com/riscv/riscv-c-api-doc/blob/master/riscv-c-api.md#architecture-extension-test-macro