Update the ghc-8.6 branch (#889)

* Revert "Bump GHC version to 8.6"

This was applied to the wrong branch; there's now a `ghc-8.6` branch;
ghc-head is always supposed to point to GHC HEAD, i.e. an odd major version.
The next version bump to `ghc-head` is supposed to go from e.g. 8.5 to 8.7

This reverts commit 5e3cf5d8868323079ff5494a8225b0467404a5d1.

* README updates (#856)

* README: Remove mentions of master branch

* README: Add instructions for using html-test

* README: Change command to run _all_ the testsuites

* README: Add project overview section

(cherry picked from commit 61d6f935da97eb96685f07bf385102c2dbc2a33c)

* Export more fixities for Hoogle (#871)

This exports fixities for more things, including class methods and
type-level operators.

(cherry picked from commit 88316b972e3d47197b1019111bae0f7f87275fce)

* Avoid line breaks due to line length in Hoogle (#868)

* Avoid line breaks due to line length in Hoogle

Hoogle operates in a line-oriented fashion, so we should avoid ever
breaking due to long lines.

One way of doing this non-intrusively is to modify the 'DynFlags' that
are threaded through the 'Hoogle' module (note this is anyways only
passed through for use in the various 'showSDoc' functions).

* Amend test case

(cherry picked from commit 657b1b3d519545f8d4ca048c06210d6cbf0f0da0)

* tyThingToLHsDecl: Preserve type synonyms that contain a forall (#880)

* tyThingToLHsDecls: Preserve type synonyms that contain a forall

Fixes #879.

* Add Note [Invariant: Never expand type synonyms]

* Clarify Note [Invariant: Never expand type synonyms]

(cherry picked from commit c3eb3f0581f69e816f9453b1747a9f2a3ba02bb9)

* Fix HEAD html-test (#860)

* Update tests for 'StarIsType'

* Accept tests

* Revert "Update tests for 'StarIsType'"

This reverts commit 7f0c01383bbba6dc5af554ee82988d2cf44e407a.

* Refactor handling of parens in types (#874)

* Fix type parenthesization in Hoogle backend

Ported the logic in the HTML and LaTeX backends for adding in parens
into something top-level in 'GhcUtil'. Calling that from the Hoogle
backend fixes #873.

* Remove parenthesizing logic from LaTeX and XHTML backends

Now, the only times that parenthesis in types are added in any backend
is through the explicit 'HsParTy' constructor. Precedence is also
represented as its own datatype.

* List out cases explicitly vs. catch-all

* Fix printing of parens for QuantifiedConstraints

The priority of printing 'forall' types was just one too high.

Fixes #877.

* Accept HTML output for quantified contexts test

* Preserve docs on type family instances (#867)

* Preserve docs on type family instances

The only problem was that the instance location was slightly off
for type family instances.

* Accept output

(cherry picked from commit 133e9c2c168db19c1135479f7ab144c4e33af2a4)

* Fix broken instance source links (#869)

The problem manifests itself in instances that are defined in
modules other than the module where the class is defined. The fix
is just to thread through the 'Module' of the instance further
along.

Since orphan instances appear to already have been working, I didn't
do anything there.

(cherry picked from commit 2de7c2acf9b1ec85b09027a8bb58bf8512e91c05)

* Add some more unicode related tests (#872)

This has been fixed for sure ever since we switched from attoparsec to
parsec. Parts of it may have been working before that, but there was a
point where this would have failed (see #191).

A regression test never hurt anyone. :)

(cherry picked from commit 5ec7715d418bfac0f26aec6039792a99a6e89370)

* Misc tests (#858)

* More tests

* spliced types
* constructor/pattern argument docs
* strictness marks on fields with argument docs

* latex test cases need seperate directory

* Accept tests

* Additional tests for the identifier parser (#816)

* Add tests for the identifier parser

* docs: Clarify how to delimit identifiers

(cherry picked from commit 0861affeca4d72938f05a2eceddfae2c19199071)

1 files changed, 12 insertions, 6 deletions

diff --git a/html-test/ref/TypeFamilies2.html b/html-test/ref/TypeFamilies2.html
index a5d0d9a9..1b4eed8c 100644
--- a/html-test/ref/TypeFamilies2.html
+++ b/html-test/ref/TypeFamilies2.html
@@ -142,8 +142,10 @@
 		    > <a href="#" class="selflink"
 		    >#</a
 		    ></td
-		  ><td class="doc empty"
-		  ></td
+		  ><td class="doc"
+		  ><p
+		    >Should be visible, but with a hidden right hand side</p
+		    ></td
 		  ></tr
 		><tr
 		><td colspan="2"
@@ -202,8 +204,10 @@
 		    > <a href="#" class="selflink"
 		    >#</a
 		    ></td
-		  ><td class="doc empty"
-		  ></td
+		  ><td class="doc"
+		  ><p
+		    >Should be visible, but with a hidden right hand side</p
+		    ></td
 		  ></tr
 		><tr
 		><td colspan="2"
@@ -240,8 +244,10 @@
 		    > <a href="#" class="selflink"
 		    >#</a
 		    ></td
-		  ><td class="doc empty"
-		  ></td
+		  ><td class="doc"
+		  ><p
+		    >External instance</p
+		    ></td
 		  ></tr
 		><tr
 		><td colspan="2"