Make mod73 test insensitive to minor variations (#9325)
Add .gitignore line for stage=1 testsuite generated file
comment update
Allow multiple entry points when allocating recursive groups (#9303)

Summary:
In this example we ended up with some code that was only reachable via
an info table, because a branch had been optimised away by the native
code generator.  The register allocator then got confused because it
was only considering the first block of the proc to be an entry point,
when actually any of the info tables are entry points.

Test Plan: validate

Reviewers: simonpj, austin

Subscribers: simonmar, relrod, carter

Differential Revision: https://phabricator.haskell.org/D88
Comments and white space
Comments and minor refactoring

- Better comments about Generalised Newtype Deriving
  See Note [Bindings for Generalised Newtype Deriving]

- Refactor the interface between TcDeriv and TcGenDeriv,
  to reduce the size of the interface of the latter.
Compiler perf has improved a bit
[backpack] Package selection

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>
Comments and white space
Test Trac #9380
Add a fast-path in TcInteract.kickOutRewritable
Comments only
Add comments about the {-# INCOHERENT #-} for Typeable (f a)

C.f. Trac #9242
Complete work on new OVERLAPPABLE/OVERLAPPING pragmas (Trac #9242)

* Deprecate -XOverlappingInstances

* Update test suite.  Several tests even had entirely unnecessary
  uses of -XOverlappingInstances

* Update user manual with a careful description of the instance
  resolution story

* Fix an outright bug in the handling of duplidate instances in GHCi,
  which are meant to silently overwrite the earlier duplicate. The
  logic was right for family instances but was both more complicated,
  and plain wrong, for class instances.  (If you are interested, the
  bug was that we were eliminating the duplicate from the InstEnv, but
  not from the [ClsInst] held in tcg_insts.)  Test is ghci044a.
Typo in comment
Fix up ghci044
Minor wordsmithing of comments
Small tweaks to comment
Typo fixes
Unbreak build.