ci: run at least some tests on older Go/LLVM versions

These should make sure basic functionality is still working.
Using the `-short` flag to avoid taking too long to run all tests (and
to install all the necessary emulators), and because some targets might
not work in older Go/LLVM versions (such as WASI).

This does _not_ run tests and checks against expected IR, because LLVM
IR changes a lot across versions.

.circleci/config.yml

@@ -90,6 +90,8 @@ commands:
               name: Check Go code formatting
               command: make fmt-check lint
       - run: make gen-device -j4
+      # TODO: change this to -skip='TestErrors|TestWasm' with Go 1.20
+      - run: go test -tags=llvm<<parameters.llvm>> -short -run='TestBuild|TestTest|TestGetList|TestTraceback'
       - run: make smoketest XTENSA=0
       - save_cache:
           key: go-cache-v4-{{ checksum "go.mod" }}-{{ .Environment.CIRCLE_BUILD_NUM }}