Revert "Add new swiftSyntax to LLDBDependencies.cmake"
Revert "Add new swiftSyntax to LLDBDependencies.cmake"

The commits creating this library are temporarily deleted
in Swift.

This reverts commit 513630b6677e67183a9329c759f9dc404de2f203.

This revert depends on https://github.com/apple/swift/pull/5864,
which is now in the tree.

apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb