Add tiny / opt to CI matrix (#448)

.github/workflows/build.yml

@@ -12,18 +12,16 @@ on:
   workflow_dispatch:
 
 jobs:
-  build:
+  matrix_on_mode:
     runs-on: ubuntu-latest
-
+    strategy:
+      matrix:
+        mode: ["", tiny, opt]
     steps:
       - uses: actions/checkout@v3
 
       - name: support ape bins
         run: sudo sh -c "echo ':APE:M::MZqFpD::/bin/sh:' >/proc/sys/fs/binfmt_misc/register"
 
-        # gh-action runners have 2 cpus with 1 thread each
-      - name: make everything
-        run: V=0 make -j2
-
-      - name: printargs.com
-        run: ./o/examples/printargs.com
+      - name: make matrix
+        run: V=0 make -j2 MODE=${{ matrix.mode }}