Prune unwanted Typeable related bindings

[TerrorJack]

GHC automatically generates Typeable related bindings in the closures for user-defined datatypes. This has the consequence of rapidly bloating the range of related rts routines and causing the linker to fail, even if we don't need anything related to Typeable at all.

We need to identify and prune Typeable related bindings generated in TcTypeable of ghc, either in the stage of codegen or linking.

[TerrorJack]

Progress: gave up pruning, instead, implemented --force switch for ahc-link, which replaces ccalls to unknown targets with trap instruction. Currently this makes the code bundle links properly, but it branches out of StgRun pre-maturely so still needs extra work.

[TerrorJack]

The premature exit of scheduler loop is due to an irrelevant issue. We'll keep the --force workaround in the foreseeable future.