Fix sysreg registers in RISC-V and modify the header patcher to not crash if a header doesn't include all tags of a generated .inc file

[moste00]

Your checklist for this pull request

• I've documented or updated the documentation of every API function and struct this PR changes.
• I've added tests that prove my fix is effective or that my feature works (if possible)

Detailed description

As per #2893, the public header riscv.h doesn't define an enum for system registers. Therefore, it was impossible to programmatically switch on the value of a system register without violating API safety (by e.g. simply duplicating the raw numbers from capstone sources).

This PR fixes this by adding enum constants in riscv.h to represent system registers.

In order to do this, the archiecture header patch tool had to be modified to not crash if a ARCH*.inc file defined several #ifdef blocks but the including header ARCH.h in capstone didn't include some of them. Previously, the ARCH.h file had to include every block of #ifdef content somewhere in it, and riscv.h doesn't need this.

Test plan

...

Closing issues

closes #2893.

[Rot127]

Good catch with the script.

[Rot127]

Sorry, before I forget, please add a test.

Never mind. Already there. But see below

[Rot127]

Also update the Python bindings.

[moste00]

@Rot127 I added tests anyway because the all the existing tests on sysregs were just asserting on their string representation in yaml, which obviously didn't catch the API problem. The unit tests I added switch on CSR registers and fail if the switch didn't match, so it will fail to compile the C test and fail at runtime for the Python test if the API changed or removed the sysreg names.

There was no need to update the Python bindings because the sysregs were already defined as integer constants (the tables mapping back and fourth from the string representation are needed in Python too).

[Rot127]

Thanks for the extra tests. It warms my pedantic heart.