[CMake] Stop some exectuable link with swiftCore
swift-compatibility-symbols, swift-def-to-strings-converter,
and swift-serialize-diagnostics don't use any Swift modules. But when
SWIFT_SWIFT_PARSER was enabled, they are linked with swiftCore. But
these binaries can be executed before the runtime is being built.
We need to stop them linking with swiftCore.
(cherry picked from commit dc6877334fb7bf33121fac75166313b25eebb600)
(cherry picked from commit 1e7c84a831ee5564d0d29af4f69915904bd8d2d9)
