Move shared code to a new crate winit-common

.github/CODEOWNERS

@@ -5,9 +5,11 @@
 /src/platform/ios.rs                @madsmtm
 /src/platform/macos.rs              @madsmtm
 /src/platform_impl/apple            @madsmtm
+/winit-common/src/core_foundation   @madsmtm
+/winit-common/src/event_handler.rs  @madsmtm
 
-# Unix
-/src/platform_impl/linux/mod.rs     @kchibisov
+# XKB
+/winit-common/src/xkb               @kchibisov
 
 # Wayland
 /src/platform/wayland.rs            @kchibisov

.github/workflows/ci.yml

@@ -184,7 +184,18 @@ jobs:
 
     - name: Test winit Android
       if: contains(matrix.platform.target, 'android')
-      run: cargo $CMD test -p winit-android --target=${{ matrix.platform.target }} --features native-activity --no-run
+      run: cargo $CMD test -p winit-android --features native-activity --no-run
+
+    - name: Test winit Common (EventHandler)
+      run: cargo $CMD test -p winit-common --features event-handler --no-run
+
+    - name: Test winit Common (CF)
+      if: contains(matrix.platform.target, 'apple')
+      run: cargo $CMD test -p winit-common --features core-foundation --no-run
+
+    - name: Test winit Common (XKB)
+      if: contains(matrix.platform.target, 'linux')
+      run: cargo $CMD test -p winit-common --features xkb,x11,wayland --no-run
 
     - name: Test winit Orbital
       if: contains(matrix.platform.target, 'redox')