Use `.hie` files for the Hyperlinker backend (#977)

# Summary

This is a large architectural change to the Hyperlinker.

  * extract link (and now also type) information from `.hie` instead
    of doing ad-hoc SYB traversals of the `RenamedSource`. Also
    adds a superb type-on-hover feature (#715).

 * re-engineer the lexer to avoid needless string conversions. By going
    directly through GHC's `P` monad and taking bytestring slices, we
    avoid a ton of allocation and have better handling of position
    pragmas and CPP.

In terms of performance, the Haddock side of things has gotten _much_
more efficient. Unfortunately, much of this is cancelled out by the
increased GHC workload for generating `.hie` files. For the full set of
boot libs (including `ghc`-the-library)

  * the sum of total time went down by 9-10% overall
  * the sum of total allocations went down by 6-7%

# Motivation

Haddock is moving towards working entirely over `.hi` and `.hie` files.
This change means we no longer need the `RenamedSource` from
`TypecheckedModule` (something which is _not_ in `.hi` files).

# Details

Along the way a bunch of things were fixed:

 * Cross package (and other) links are now more reliable (#496)
 * The lexer tries to recover from errors on every line (instead of at CPP
    boundaries)
 * `LINE`/`COLUMN` pragmas are taken into account
 * filter out zero length tokens before rendering
 * avoid recomputing the `ModuleName`-based `SrcMap`
 * remove the last use of `Documentation.Haddock.Utf8` (see  #998)
 * restructure temporary folder logic for `.hi`/`.hie` model

1 files changed, 104 insertions, 93 deletions

diff --git a/hypsrc-test/ref/src/CPP.html b/hypsrc-test/ref/src/CPP.html
index fb85bd2f..2ebcae90 100644
--- a/hypsrc-test/ref/src/CPP.html
+++ b/hypsrc-test/ref/src/CPP.html
@@ -11,8 +11,8 @@
       ><span
       >
 </span
-      ><a name="line-2"
-      ></a
+      ><span id="line-2"
+      ></span
       ><span class="hs-keyword"
       >module</span
       ><span
@@ -23,45 +23,48 @@
       > </span
       ><span class="hs-keyword"
       >where</span
-      ><span
-      >
-</span
-      ><a name="line-3"
-      ></a
-      ><span
-      >
-</span
-      ><a name="line-4"
-      ></a
       ><span class="hs-cpp"
-      >#define SOMETHING1
+      >
+
+#define SOMETHING1
 </span
       ><span
       >
 </span
-      ><a name="line-6"
-      ></a
-      ><span class="hs-identifier"
-      >foo</span
+      ><span id="line-6"
+      ></span
+      ><span class="annot"
+      ><a href="CPP.html#foo"
+	><span class="hs-identifier hs-type"
+	  >foo</span
+	  ></a
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
       >::</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-identifier hs-type"
-      >String</span
+	>String</span
+	></span
       ><span
       >
 </span
-      ><a name="line-7"
-      ></a
-      ><a name="foo"
-      ><a href="CPP.html#foo"
-	><span class="hs-identifier"
-	  >foo</span
-	  ></a
-	></a
+      ><span id="line-7"
+      ></span
+      ><span id="foo"
+      ><span class="annot"
+	><span class="annottext"
+	  >foo :: String
+</span
+	  ><a href="CPP.html#foo"
+	  ><span class="hs-identifier hs-var hs-var"
+	    >foo</span
+	    ></a
+	  ></span
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
@@ -74,142 +77,150 @@
        -}</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-string"
-      >&quot;foo&quot;</span
-      ><span
-      >
-</span
-      ><a name="line-10"
-      ></a
-      ><span
-      >
-</span
-      ><a name="line-11"
-      ></a
+	>&quot;foo&quot;</span
+	></span
       ><span class="hs-cpp"
-      >#define SOMETHING2
+      >
+
+#define SOMETHING2
 </span
       ><span
       >
 </span
-      ><a name="line-13"
-      ></a
-      ><span class="hs-identifier"
-      >bar</span
+      ><span id="line-13"
+      ></span
+      ><span class="annot"
+      ><a href="CPP.html#bar"
+	><span class="hs-identifier hs-type"
+	  >bar</span
+	  ></a
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
       >::</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-identifier hs-type"
-      >String</span
+	>String</span
+	></span
       ><span
       >
 </span
-      ><a name="line-14"
-      ></a
-      ><a name="bar"
-      ><a href="CPP.html#bar"
-	><span class="hs-identifier"
-	  >bar</span
-	  ></a
-	></a
+      ><span id="line-14"
+      ></span
+      ><span id="bar"
+      ><span class="annot"
+	><span class="annottext"
+	  >bar :: String
+</span
+	  ><a href="CPP.html#bar"
+	  ><span class="hs-identifier hs-var hs-var"
+	    >bar</span
+	    ></a
+	  ></span
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
       >=</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-string"
-      >&quot;block comment in a string is not a comment {- &quot;</span
-      ><span
-      >
-</span
-      ><a name="line-15"
-      ></a
-      ><span
-      >
-</span
-      ><a name="line-16"
-      ></a
+	>&quot;block comment in a string is not a comment {- &quot;</span
+	></span
       ><span class="hs-cpp"
-      >#define SOMETHING3
+      >
+
+#define SOMETHING3
 </span
       ><span
       >
 </span
-      ><a name="line-18"
-      ></a
+      ><span id="line-18"
+      ></span
       ><span class="hs-comment"
       >-- &quot; single quotes are fine in line comments</span
       ><span
       >
 </span
-      ><a name="line-19"
-      ></a
+      ><span id="line-19"
+      ></span
       ><span class="hs-comment"
       >-- {- unclosed block comments are fine in line comments</span
       ><span
       >
 </span
-      ><a name="line-20"
-      ></a
+      ><span id="line-20"
+      ></span
       ><span
       >
 </span
-      ><a name="line-21"
-      ></a
+      ><span id="line-21"
+      ></span
       ><span class="hs-comment"
       >-- Multiline CPP is also fine</span
-      ><span
-      >
-</span
-      ><a name="line-22"
-      ></a
       ><span class="hs-cpp"
-      >#define FOO\
+      >
+#define FOO\
   1
 </span
       ><span
       >
 </span
-      ><a name="line-25"
-      ></a
-      ><span class="hs-identifier"
-      >baz</span
+      ><span id="line-25"
+      ></span
+      ><span class="annot"
+      ><a href="CPP.html#baz"
+	><span class="hs-identifier hs-type"
+	  >baz</span
+	  ></a
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
       >::</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-identifier hs-type"
-      >String</span
+	>String</span
+	></span
       ><span
       >
 </span
-      ><a name="line-26"
-      ></a
-      ><a name="baz"
-      ><a href="CPP.html#baz"
-	><span class="hs-identifier"
-	  >baz</span
-	  ></a
-	></a
+      ><span id="line-26"
+      ></span
+      ><span id="baz"
+      ><span class="annot"
+	><span class="annottext"
+	  >baz :: String
+</span
+	  ><a href="CPP.html#baz"
+	  ><span class="hs-identifier hs-var hs-var"
+	    >baz</span
+	    ></a
+	  ></span
+	></span
       ><span
       > </span
       ><span class="hs-glyph"
       >=</span
       ><span
       > </span
+      ><span class="annot"
       ><span class="hs-string"
-      >&quot;line comment in a string is not a comment --&quot;</span
+	>&quot;line comment in a string is not a comment --&quot;</span
+	></span
       ><span
       >
 </span
-      ><a name="line-27"
-      ></a
+      ><span id="line-27"
+      ></span
       ></pre
     ></body
   ></html