hadrian/compiler: implement targetRTSLinkerOnlySupportsSharedLibs

This patch implements the targetRTSLinkerOnlySupportsSharedLibs
predicate in hadrian. Its definition in hadrian is the single source
of truth, and the information propagates to ghc settings file, ghc
driver and testsuite driver. It is used in various places to ensure
dynamic dependency is selected when the target RTS linker only
supports loading dynamic code.

(cherry picked from commit 8c74a0ed)