Example P4 program where const gives error when used as bit slice low/high value

[jafingerhut]

I tried reporting a different program that I thought gave a similar error before, and closed it because I could not reproduce it, but this one gives the error with a recent version of p4c source code:

$ git clone https://github.com/jafingerhut/p4-guide
$ cd p4-guide/loop-test-progs
$ p4test err-const-is-not-compile-time-known-value1.p4 
err-const-is-not-compile-time-known-value1.p4(57): [--Werror=type-error] error: i: slice bit index values must be constants
            n[i:i] = 1;
              ^

$ p4test --version
p4test
Version 1.2.4.16 (SHA: d2006d52e BUILD: RELEASE)