>  Is Anthony's CL to be abandoned in favour of the change to the Plan 9 C compiler (give or take the other nit of a "static" definition)?

see my earlier remark:

"it's reasonable to use any integer type in a switch, although the compilers don't currently support it.
it's compatible with the standard, which allows any integer type. *i'd cancel the change request and work round it* (eg, add a cast) until
the compilers can be changed to support it."

Instead of making a small patch to the Go file locally, you could also apply Russ's change locally to 8c, which might be easier.
That change will keep you going, but it doesn't look like a good one as it stands to apply to the full compiler suite.
As my remark above suggests, the compiler suite should, however, support using any integer type in a switch.