Add macOS simulator build to pipelines (#162)

- GitHub actions changed to build simulator on macOS (it's broken, but at least we get a good code portability check for now!)
- `Buildscripts/` shell scripts updated to use `/bin/sh` so it works on macOS too
- Various includes fixed in various subprojects so the code is more portable

.github/actions/build-simulator/action.yml

@@ -7,6 +7,9 @@ inputs:
   platform_name:
     description: A descriptive name for the target platform (e.g. amd64, aarch64, etc.)
     required: true
+  publish:
+    description: A boolean that enables publishing of artifacts
+    required: true
 
 runs:
   using: "composite"
@@ -16,7 +19,7 @@ runs:
       with:
         submodules: recursive
     - name: Install Linux Dependencies for SDL
-      if: ${{ inputs.platform_name }} == 'linux'
+      if: ${{ runner.os == 'Linux' }}
       shell: bash
       # See Libraries/SDL/docs/README-linux.md
       run: >
@@ -45,6 +48,7 @@ runs:
       run: Buildscripts/release-simulator.sh buildsim release/Simulator-${{ inputs.os_name }}-${{ inputs.platform_name }}
     - name: 'Upload Artifact'
       uses: actions/upload-artifact@v4
+      if: ${{ inputs.publish == 'true' }}
       with:
         name: Simulator-${{ inputs.os_name }}-${{ inputs.platform_name }}
         path: release/Simulator-${{ inputs.os_name }}-${{ inputs.platform_name }}