Where is the documentation of the LLVM Pass InstCombine? Is it accurate? Is there any default example? Is it tested?

Compiler guys love generated code. So in our obfuscating compiler, we have a declarative format to specify tons of stuff on our passes: its name, it's application level, its documentation, a sample usage, its options (with default values, help string etc), but also it's priority in the pass pipeline and a few other stuff specific to a code obfuscator. And everything is consistent, from sphinx-generated documentation to inline help and even tests! Let's have a look at this, and maybe influence the way it's done in LLVM.