In practice they are classified into MCSL (Mildly Context-Sensitive) subcategory defined by Aravind K. Joshi.
No reason to do that though, except to validate some random persons perspective on language. The sky will not open and smash us with a giant foot if we reject such an obligation.
With ~17 years of experience already, start with the study of the structure of C programs. Recreate some of it manually, build it, and research the things that do not behave as expected.
Bonus of using an open source kernel is they have a lot of eyeballs on them. They will be pretty dialed in versus studying random Github projects that happen to be written in C.
Would recommend avoiding cognitive overload, wait until you get into comfortable flow writing, building, fixing as needed, simple programs before you dive into lower level debugging, trying to grasp assembly structures that a compiler spits out.
Sure, linguists, glad you found some semantics that fit your obsession. Happy for you!
Most people will never encounter their work and live their lives never knowing such an event happened.