CI: add non-LLVM backends to the test matrix

We can't yet run the behavior tests with stage3, but at least we can run
them with stage2, and we can use the proper test matrix.

This commit also adds use_llvm and ofmt to the zig build system.
496eb69273Andrew Kelley committed on 5/6/2022, 5:29:25 AMparentdf38dfa
4 files changedLine totals unavailable