[commit: ghc] wip/gadtpm's head updated: Mainly some top-level comments (3b6f7c8)

[git at git.haskell.org]

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

Branch 'wip/gadtpm' now includes:

     4c4a0a5 Fix docstring GHC.IO.Handle.FD.openFileBLocking
     4c11db6 sphinx-build: fix python stack overflow (Trac #10950)
     b617e9f Improve comments in CmmSwitch
     85e147e Always run test T9407
     36b174d Add expected stderr for #11466 test case
     adb721b Make a constraint synonym for repeated BinaryStringRep and use it.
     835a2a2 Default non-canonical CallStack constraints
     2df4221 Add tests for #11465 and the kind invariant
     9048c3d Don't print "Loaded GHCi configuration" message in ghc -e (#11478)
     65881c0 Mark some ghci tests as req_interp
     6e5f828 Fix a formatting error in the user's guide
     4d51bfc Do not count void arguments when considering a function for loopification.
     b01288d rts: Disable tick timer unless really needed
     4e04043 Add test for Trac #11056
     f42db15 Remove unused IND_PERM
     06c2547 Small doc fix
     7cd37c5 Give a more verbose error message when desugaring a HsTypeOut
     8e9a870 Remove -Wredundant-superclasses from standard warnings
     1be8491 mkUserGuidePart: Better flag cross-referencing
     6f96109 user-guide: Reformat warning lists
     b5e52bf user-guide: Fix typos
     ec87788 Don't add ticks around type applications (#11329)
     923d215 user-guide: Document -L RTS flag
     89bdac7 Add test for #11473
     8b5ea7c User's guide: fix singular/plural typo in flagnames
     98d6a29 Docs: delete section on Hierarchical Modules
     edc68b2 Remove `replaceDynFlags` from `ContainsDynFlags`
     2c6fe5b Add -fwarn-redundant-constrains to test for #9708
     fd6dd41 Implement `-Wnoncanonical-monadfail-instances` warning
     ff21795 Special-case implicit params in superclass expansion
     746764c Refactor validity checking for type/data instances
     42c6263 Avoid recursive use of immSuperClasses
     f7e0e5f Improve tracing in checkValidInstance
     3c060f3 Fix exprIsHNF (Trac #11248)
     5c82333 Show error message for unknown symbol on Elf_Rel platforms
     edb30fd Comments only: more alternate names for ARM registers [skip ci]
     bc1e085 HscTypes: Fix typo in comment
     132c208 Rename -Wmissing-monadfail-instance to plural-form
     6e2658f Better document behavior of -Wmissed-specialisations
     128b678 user-guide: Note order-dependence of flags
     f0f63b3 Implement -Wunrecognised-warning-flag
     9fe7d20 Ensure that we don't produce code for pre-ARMv7 without barriers
     632f020 Less verbose output for the in-scope set
     cf788a5 White space only
     47b3f58 Add "ticks-exhausted" comment
     1c6d70c Kill off zipTopTCvSubst in favour of zipOpenTCvSubst
     016a0bd Fix two cloning-related bugs
     34c9a4e Missed plural renaming in user's guide
     5f5dc86 Minor users-guide markup fixup [skip ci]
     9b71695 Update transformers submodule to 0.5.1.0 release
     f1885df Update process submodule to 1.4.2.0 release
     3798b2a Fix three broken tests involving exceptions
     01809bc Pass InScopeSet to substTy in lintTyApp
     e24a9b5 Nicer error on +RTS -hc without -rtsopts or -prof
     6d2bdfd Fix segmentation fault when .prof file not writeable
     6817703 Split off -Wunused-type-variables from -Wunused-matches
     144ddb4 Construct in_scope set in mkTopTCvSubst
     eeb67c9 Testsuite: fixup req_profiling tests (#11496)
     e2bdf03 Build profiling libraries on `validate --slow` (#11496)
     44a5d51 Enable RemoteGHCi on Windows
     45fd83b Fix a typo in the note name in comments
     448ea97 Typos in comments
     1f6d142 ghci: fix trac issue #11481
     1c6130d rts/Timer: Actually fix #9105
     0dc7b36 Restore original alignment for info tables
     0d92d9c Use stage1 build variables when building the RTS
     d50609e Test for undef bugs in the LLVM backend when validating
     45c6fbc Document -fllvm-fill-undef-with-garbage
     4faa1a6 s/unLifted/unlifted for consistency
     2899aa5 Fix some substitution InScopeSets
     00cbbab Refactor the typechecker to use ExpTypes.
     5dcae88 Rename "open" subst functions
     85daac5 Fix cost-centre-stack bug when creating new PAP (#5654)
     a496f82 Remote GHCi: create cost centre stacks in batches
     71b1183 Update profiling test output
     0d5ddad fix validate breakage
     30a4631 Overhaul the Overhauled Pattern Match Checker
     3b6f7c8 Mainly some top-level comments