Previously no attempt was made to avoid multiple threads writing their
capability-local eventlog buffers to the eventlog writer simultaneously.
This could result in multiple eventlog streams being interleaved. Fix
this by documenting that the EventLogWriter's write() and flush()
functions may be called reentrantly and fix the default writer to
protect its FILE* by a mutex.

Fixes #18210.

This patch updates file paths according to new module hierarchy [1]:

  * GHC/Core.hs                <= coreSyn/CoreSyn.hs
  * GHC/Core/Coercion.hs       <= types/Coercion.hs
  * GHC/Core/Coercion/Axiom.hs <= types/CoAxiom.hs
  * GHC/Core/Coercion/Opt.hs   <= types/OptCoercion.hs
  * GHC/Core/DataCon.hs        <= basicTypes/DataCon.hs
  * GHC/Core/FamInstEnv.hs     <= types/FamInstEnv.hs
  * GHC/Core/Lint.hs           <= coreSyn/CoreLint.hs
  * GHC/Core/Subst.hs          <= coreSyn/CoreSubst.hs
  * GHC/Core/TyCo/Rep.hs       <= types/TyCoRep.hs
  * GHC/Core/TyCon.hs          <= types/TyCon.hs
  * GHC/Core/Type.hs           <= types/Type.hs
  * GHC/Core/Unify.hs          <= types/Unify.hs
  * GHC/Types/Literal.hs       <= basicTypes/Literal.hs
  * GHC/Types/Var.hs           <= basicTypes/Var.hs

[1]: https://gitlab.haskell.org/ghc/ghc/-/wikis/Make-GHC-codebase-more-modular

[skip ci]

We should allow a wrapper with up to 82 parameters when the original
function had 82 parameters to begin with.

I verified that this made no difference on NoFib, but then again
it doesn't use huge records...

Fixes #18122.

See `testsuite/tests/hiefile/should_run/HieQueries.hs` and
`testsuite/tests/hiefile/should_run/HieQueries.stdout` for an example of this

We add two new fields, `EvidenceVarBind` and `EvidenceVarUse` to the
`ContextInfo` associated with an Identifier. These are associated with the
appropriate identifiers for the evidence variables collected when we come across
`HsWrappers`, `TcEvBinds` and `IPBinds` while traversing the AST.

Instance dictionary and superclass selector dictionaries from `tcg_insts` and
classes defined in `tcg_tcs` are also recorded in the AST as originating from
their definition span

This allows us to save a complete picture of the evidence constructed by the
constraint solver, and will let us report this to the user, enabling features
like going to the instance definition from the invocation of a class method(or
any other method taking a constraint) and finding all usages of a particular
instance.

Additionally,

- Mark NodeInfo with an origin so we can differentiate between bindings
  origininating in the source vs those in ghc
- Along with typeclass evidence info, also include information on Implicit
  Parameters
- Add a few utility functions to HieUtils in order to query the new info

Updates haddock submodule

emptyModBreaks contains a bottom and consequently it's important that we
don't use it unless necessary.

This just seems like a good idea.

This could otherwise easily cause a leak of (+) thunks.

To determine whether the module is a boot module
Coverage.addTicksToBinds was checking for a `boot` suffix in the module
source filename. This is quite ad-hoc and shouldn't be necessary; the
callsite in `deSugar` already checks that the module isn't a boot
module.

As noted in !3132, this has rather severe knock-on consequences in
user-code. We'll need to revisit this before merging something along
these lines.

This reverts commit 9749fe12.

The tokens `[|`, `|]`, `(|`, and `|)` are opening/closing tokens as
described in GHC Proposal #229. This commit makes the unicode
variants (`⟦`, `⟧`, `⦇`, and `⦈`) act the same as their ASCII
counterparts.

Fixed by @alp (see ghc/ghc#16051 (comment 274265))

`Ordering` needs to be wired in for use in the built-in `CmpNat` and
`CmpSymbol` type families, but somehow it was never added to the list
of `wiredInTyCons`, leading to the various oddities observed
in #18185. Easily fixed by moving `orderingTyCon` from
`basicKnownKeyNames` to `wiredInTyCons`.

Fixes #18185.

See discussion in #13009 (comment 268610)

The immediate goal is let the hie-bios.bat script
set CABFLAGS with `-v0` and remove all cabal output
except the compiler arguments

It is a direct translation of the sh script

This can be used to tell git to ignore bulk renaming commits like the
recently-finished module hierarchy refactoring. Configured with,

    git config blame.ignoreRevsFile .git-ignore-revs

Fixes #18206.

Fixes #17926.

 - `forAllOrNothing` now is monadic, so we can trace whether we bind
   an explicit `forall` or not.

 - #18145 arose because the free vars calculation was needlessly
   complex. It is now greatly simplified.

 - Replaced some other implicit var code with `filterFreeVarsToBind`.
Co-authored-by: Ryan Scott <ryan.gl.scott@gmail.com>

This fixes #17619, where a tick snuck in to the template of a rule,
resulting in a panic during rule matching. The tick in question was
introduced via post-inlining, as discussed in `Note [Simplifying
rules]`. The solution we decided upon was to simply ignore ticks in the
rule template, as discussed in `Note [Tick annotations in RULE
matching]`.

Fixes #18162.
Fixes #17619.

This function and its accompanying rule resolve issue #5218.
A future PR to the bytestring library will make the internal
Data.ByteString.Internal.unsafePackAddress compute string length
with cstringLength#. This will improve the status quo because it is
eligible for constant folding.

Additionally, introduce a new data constructor to ForeignPtrContents
named FinalPtr. This additional data constructor, when used in the
IsString instance for ByteString, leads to more Core-to-Core
optimization opportunities, fewer runtime allocations, and smaller
binaries.

Also, this commit re-exports all the functions from GHC.CString
(including cstringLength#) in GHC.Exts. It also adds a new test
driver. This test driver is used to perform substring matches on Core
that is dumped after all the simplifier passes. In this commit, it is
used to check that constant folding of cstringLength# works.

[skip ci]

It doesn't belong into GHC.Unit.State

Previously, we sorted according to the test name and way,
but the metrics (max_bytes_used/peak_megabytes_allocated etc.)
were appearing in nondeterministic order.

The testcase works now.
See explanation in #11506 (comment 273202)

We changed to use variable length encodings for many types by default,
including Word32. This makes sense for numbers but not when Word32 is
meant to represent four bytes.

I added a FixedLengthEncoding newtype to Binary who's instances
interpret their argument as a collection of bytes instead of a number.

We then use this when writing/reading magic numbers to the iface file.

I also took the libery to remove the dummy iface field.

This fixes #18180.

* Besides resizing functions, shrinking ones also mutate the
  size of a mutable array and because of those two `sizeofMutabeByteArray`
  and `sizeofSmallMutableArray` are now deprecated
* Change reference in documentation to the newer functions `getSizeof*`
  instead of `sizeof*` for shrinking functions
* Fix incorrect mention of "byte" instead of "small"

They used to be strict until 4d2ac2d4 (9 years ago).

It's obviously better to be strict for performance reasons.
It also blocks #18067.

NoFib results:

```
--------------------------------------------------------------------------------
        Program         Allocs    Instrs
--------------------------------------------------------------------------------
        integer          -1.1%     +0.4%
   wheel-sieve2         +21.2%    +20.7%
--------------------------------------------------------------------------------
            Min          -1.1%     -0.0%
            Max         +21.2%    +20.7%
 Geometric Mean          +0.2%     +0.2%
```

The regression in `wheel-sieve2` is due to reboxing that likely will go
away with the resolution of #18067. See !3282 for details.

Fixes #18187.