add support for mcountinhibit CSR

[cyyself]

We hardwired mcountinihibit to 0 previously. Now, we implemented it.

[aswaterman]

Please don't edit encoding.h directly, as this is an auto-generated file from https://github.com/riscv/riscv-opcodes

Note also when you update encoding.h over there, you should use 1U rather than 1ULL for these constants, which will minimize friction when using them in places where the underlying datatype is not long long. After all, they are very small numbers.

Otherwise, the changes LGTM.

[cyyself]

Please don't edit encoding.h directly, as this is an auto-generated file from https://github.com/riscv/riscv-opcodes

Fixed.

Note also when you update encoding.h over there, you should use 1U rather than 1ULL for these constants, which will minimize friction when using them in places where the underlying datatype is not long long. After all, they are very small numbers.

Fixed. I checked the ISA spec. The mcounteren and mcountinhibit are 32-bit wide CSR, so using 1U is enough.

Otherwise, the changes LGTM.

Thanks!

[aswaterman]

LGTM now, thanks for the contribution.

[cyyself]

Is this PR ready to merge?

[aswaterman]

Yes, thanks for the ping.