[CI] sep build

Author: MikailBag

.github/workflows/rust.yml

@@ -71,7 +71,16 @@ jobs:
         with: 
           toolchain: nightly
           override: true
-      - name: Compile tests
+      - name: Compile tests (Linux)
+        if: matrix.os == 'ubuntu-20.04'
+        run: |
+          rm -r .cargo
+          cd minion-tests
+          $TARGET=${{ matrix.target }}
+          rustup target add $TARGET
+          cargo build -Zunstable-options --out-dir=../out --target=$TARGET     
+      - name: Compile tests (Windows)
+        if: matrix.os == 'windows-2019'
         run: |
           rm -r .cargo
           cd minion-tests