[commit: ghc] wip/erikd/rts's head updated: rts: Add `-Wundef` to CFLAGS and fix warnings (4c1cb82)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

Branch 'wip/erikd/rts' now includes:

     770d708 Add ghc-boot-th to rules/foreachLibrary
     dc94914 Document determinism in shortOutIndirections
     3f3dc23 Testsuite: run tests in /tmp after copying required files
     1a9ae4b Testsuite: delete old cleanup code (#11980)
     a9dd9b7 Testsuite: delete unused file [skip ci]
     c92cfbc Testsuite: don't skip concio001 and concio001_thr
     931b3c7 Delete libraries/ghci/GNUmakefile [skip ci]
     a54d87a rules: Fix name of ghc-boot-th library
     5d80d14 rules/build-prog: Ensure programs depend upon their transitive deps
     33c029d rts: More const correct-ness fixes
     b088c02 Testsuite: T10052 requires interpreter (#11730)
     3251743 Testsuite: don't warn when mk/ghcconfig_* hasn't been created yet
     77ee3a9 Update .mailmap [skip ci]
     fffe3a2 Make inert_model and inert_eqs deterministic sets
     f0f0ac8 Fix histograms for ticky code
     ba3e1fd Add a test for #11108
     39a2faa Rework parser to allow use with DynFlags
     310371f rts: Add isPinnedByteArray# primop
     f091218 CLabel: Catch #11155 during C-- pretty-printing
     9dd0481 Add (broken) test for #12063.
     5f1557e Failing test case for #12076.
     f18e8d8 rts: Add missing `const` from HashTable API
     6282bc3 Kill varSetElems in tidyFreeTyCoVars
     13e40f9 Kill varEnvElts in tcPragExpr
     4c1cb82 rts: Add `-Wundef` to CFLAGS and fix warnings