Revert "Add workaround for building executables with older CMake versions."

[compnerd]

Reverts #619

This breaks the Windows build. I'd like to revert this and re-enable it with a fix for Windows.

[compnerd]

@swift-ci please test

[compnerd]

RPATH is a bad thing to use - please never use it directly, use CMake to control rpaths

[artemcm]

Ah. This means that swiftlang/swift#37122 needs to be reverted as well because it depends on it.

@compnerd, #619 is working around the fact that rpath is automatically propagated in CMake >= 3.17, but not 3.16. What would an alternative workaround look like?

[compnerd]

Is this for testing purposes or for distribution purposes?

[artemcm]

This is for the driver that gets built in the build directory of swift, and gets configured to be the default compiler driver in swiftlang/swift#37122.

For the driver that gets built to be distributed, we have rpaths configured in https://github.com/apple/swift-driver/blob/main/Utilities/build-script-helper.py.

[artemcm]

To clarify, when just building swift, and using the build directory compiler, this is used.

When we run --install-swift-driver, rpaths are configured separately in the build-script-helper.py.

[compnerd]

The question still stands: is it for testing or do you intend these paths to be used on a random host (this is a problem because rpaths are an attack vector)

[artemcm]

This is for use by compiler developers only, in the compiler build directory. It is not meant to be distributed or to be used on a random host.

[compnerd]

Ah, okay, then you should be using the BUILD_RPATH property on the targets.

[compnerd]

See #642 for a possible fix