Bring back i686-pc-windows-gnullvm target

Author: mati865

src/ci/github-actions/jobs.yml

@@ -686,8 +686,10 @@ auto:
   - name: dist-aarch64-llvm-mingw
     env:
       SCRIPT: python x.py dist bootstrap --include-default-paths
+      # i686 has no dedicated job, build it here because this job is fast
       RUST_CONFIGURE_ARGS: >-
         --build=aarch64-pc-windows-gnullvm
+        --target=aarch64-pc-windows-gnullvm,i686-pc-windows-gnullvm
         --enable-full-tools
         --enable-profiler
       DIST_REQUIRE_ALL_TOOLS: 1