Revert "Add link between swiftBasic and swiftAST"

This reverts commit 9010813.

Author: CodaFi

lib/Basic/CMakeLists.txt

@@ -98,10 +98,6 @@ target_link_libraries(swiftBasic PUBLIC
 target_link_libraries(swiftBasic PRIVATE
   ${UUID_LIBRARIES})
 
-# This is because swiftBasic uses InFlightDiagnostic::flush, which is defined
-# in swiftAST. This is a cyclic link dependency and it should be removed.
-target_link_libraries(swiftBasic PUBLIC swiftAST)
-
 message(STATUS "Swift version: ${SWIFT_VERSION}")
 message(STATUS "Swift vendor: ${SWIFT_VENDOR}")