Specify 'simulator' environment explicitly
Specify 'simulator' environment explicitly

Clang understands `simulator` as a [valid environment](https://github.com/llvm/llvm-project/blob/657adcb0779d2d119737f2ca557a87456024a5ac/llvm/include/llvm/ADT/Triple.h#L231)
like `macabi` for Catalyst builds. It makes explicit
that the build is targeted at the Simulator. Otherwise,
`arm64-apple-ios11.0` is an iOS build which it tries to
link to the iPhoneSimulator SDK.

leetal/ios-cmake