[WIP] Detection of ARM THUMB context switch

[TheN00bBuilder]

Your checklist for this pull request

• [v] I've read the guidelines for contributing to this repository
• [v (WIP) ] I made sure to follow the project's coding style
• [] I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

This is a WIP / Draft merge for my work on detecting ARM THUMB context switches. This can only be done when the A2 encoding of the blx instruction is encountered, which I am detecting and handling. See A8-346 of the "ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition."

Keep in mind I've yet to clean up artifacts, prints, and other things from the MR, so don't judge too hard the cleanliness until I say otherwise haha. I've also yet to "de-magic" some numbers with defines.

Test plan

I have not written tests yet for this, but I do have an example binary that I have patched from the original issue (#4357) attached here, that will be taken into consideration when writing tests.

Closing issues

closes #4357

p2kmod.zip

[karliss]

Few advices beside the stuff I wrote in #4357 .

When working on an issue, create a branch for that specific fix and do your work there. Don't work in the dev branch of your github fork.

Having a RZ_ANALYSIS_OP_TYPE_CTX_SWITCH bitwise flag and introducing instruction type RZ_ANALYSIS_OP_TYPE_CTX_SWITCH are two completely different things. Although based on my previous comment both might be unnecessary.