SI-7109 SI-7153 Generalize the API to get docComments: allow to force docTrees
for given fragments. Don't type-check when forcing doc comments, but rather
 do it directly. Test the new functionality as well as better tests for
the old one.
Name boolean arguments in src/compiler.

What would you prefer?

  adaptToMemberWithArgs(tree, qual, name, mode, false, false)

Or:

  adaptToMemberWithArgs(tree, qual, name, mode, reportAmbiguous = false, saveErrors = false)
Name boolean arguments in src/reflect.
Name boolean arguments in src/library.
Check named-args-for-clarity incur no extra bytecode

When named arguments correspond the the parameter declaration
order, the compiler should not lift out assignments before
the method call, as it would have to do for out-of-order
arguments.

Confirm this with a bytecode comparison test.
SI-7214 outer check based on dealiased pattern type.

A Typed Pattern (_: T) is more than `.isInstanceOf`: if `T` is a
path dependent type, the scrutinee's $outer reference is also
compared against the prefix of `T`.

The code that synthesises this is split into two places.
`needsOuterCheck` determines whether to add this check, based on
the type `T`, and the type of the scrutinee. If it gives the
go-ahead, `treeCondStrategy.outerCheck` synthesizes the check.

The new test case demonstrates the problems caused by the failure
to dealias in `needsOuterCheck`: it could either wrongly lead to
synthesis of an outer test (which would crash), or wrongly omit
the outer test (meaning overly liberal matching.)

A simple `dealias` remedies this. `dealiasWiden` is *not*
appropriate here; we need to keep hold of singleton types.

I'll also note that there is already a little slack between these
methods, as commented:

> ExplicitOuter replaces `Select(q, outerSym) OBJ_EQ expectedPrefix`
> by `Select(q, > outerAccessor(outerSym.owner)) OBJ_EQ expectedPrefix`
> if there's an outer accessor, otherwise the condition becomes `true`
> TODO: can we improve needsOuterTest so there's always an outerAccessor?

So this is probably a fragile area that warrants a careful review
with a view to design improvements.
Merge pull request #2156 from vigdorchik/hierarchy

SI-7109 SI-7153 Generalize the API to get docComments: allow to force do...
Merge pull request #2199 from retronym/ticket/7214

SI-7214 outer check based on dealiased pattern type.
Merge pull request #2203 from paulp/topic/bool-arg-rebased

Name boolean arguments (rebased)
Merge 2.10.x into master. The non-conflicting part.

This merges #2083 and its reversion (synchronization for reflection),
and everything else that can be merged automatically.
Merge 2.10.x into master.
Merge 2.10.x into master.
Merge 2.10.x into master.
Merge 2.10.x into master.
No-op merge for [nomaster] part of 2.10.x