While the GNU assembler allows use of 'i' (immediate) constraints on
inline assembly when generic a string that is a numeric constant, clang
does not.  In fact, clang crashes, but David is unable to reproduce that
in is setup, and instead gets a proper warning telling you not to do
silly things.  Switch to using C strings rather than immediat constraints.
Merge branch 'master' of https://github.com/CTSRD-CHERI/cheribsd