self-profile: Support arguments for generic_activities.
This PR adds support for recording arguments of "generic activities". The most notable use case is LLVM module names, which should be very interesting for `crox` profiles. In the future it might be interesting to add more fine-grained events for pre-query passes like macro expansion.
I tried to judiciously de-duplicate existing self-profile events with `extra_verbose_generic_activity`, now that the latter also generates self-profile events.
r? @wesleywiser
The codegen crate contains the code to convert from MIR into LLVM IR,
and then from LLVM IR into machine code. In general it contains code
that runs towards the end of the compilation process.
For more information about how codegen works, see the rustc guide.