Currently there are vm options like -XX:+UseRVA20U64 and -XX:+UseRVA22U64 on riscv to indicate the supported riscv extension via profiles.
These profiles should be updated to reflect the full supported extensions and new profile like UseRVA23U64 should be added.

check riscv profiles:
https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#rva20-profiles
https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#rva22-profiles
https://github.com/riscv/riscv-profiles/blob/main/rva23-profile.adoc#rva23u64-profile

also check what's in llvm:
https://github.com/llvm/llvm-project/commit/b44771f48038