Address performance of smart indenter at end of file with inactive regions

Skip custom attribute statistics calculation for EnC deltas

Fixes #3485
Closes #3488

fixed project host cache leak.

Fix typos: trimedText => trimmedText

MetadataVisualizer: CustomAttribute blob usage statistics

Fix Issue #2569 DirectiveTriviaSyntax.GetRelatedDirectives assumes there can only be one #elif

Add missing references to InteractiveComponents

[Automated] Merge 'stabilization' into 'master'

Add ClrOnlyFact attribute to InteractiveExtensionMethods test

Remove the term "whitelist"

**Bug:** Fixes DevDiv Bug 1185799

**Customer Scenario**
No customer scenario, per se.

There are a number of places where we use the term "whitelist", and one of them (a code comment) was flagged by Policheck. Given that our code is open I've gone ahead and simply fixed them all.

**Fix**
Several internal types were updated with new names, as well as various fields, locals, and a comment.

**Testing**
After the fix, the code still passes all of our unit and integration tests.

We have a couple of places where we check that the set of analyzer
assemblies is internally consistent and complete--that is, for any given
assembly in that set, all of its dependencies are satisfied by other
assemblies in the set.

We expect certain dependencies to be satisfied by the host, and so want
to ignore them if they are not found in the the analyzer assembly set.
We referred to these host-provided dependencies as a white list, but
Policheck does not like that term. Instead, we now refer to these as the
"ignorable assembly list".

Update DefineExtensionMethods test

Allow extension methods in script code

[Automated] Merge 'stabilization' into 'master'

Pass (IntPtr)(-1) to ThrowExceptionForHR calls to ignore existing error info

Build samples in Jenkins

Fix bad errors in the error list -- bug 1166689 

Calculate correct set of events in the VB navigation bar

Do not attempt to prepare for an event hookup for a Handles clause in an invalid context.

Gracefully handle bad label lookups

Fixes internal bugs #1185589 (currently active in "1.0 (stable)") and #530506

There are two places in VB where we display custom lists of events in the navigation bar:
1. In a type declaration with declared events (directly or in any base type or interface), the middle dropdown shows a "(<Type> Events)" node that then lists all of its events in the right dropdown.
2. WithEvents fields are each shown as a separate node in the middle dropdown, which then list all of the accessible events on that type (or its base types or interfaces) in the right dropdown.

In either case, selecting an event from the right dropdown generates a method that Handles the event (or navigates to an existing method that Handles the event).

To calculate the list the events to show for code generation, we previously iterated through its BaseType chain gathering up IEventSymbols with the needed accessibility levels. This approach had two known problems:

1. It was not considering interface implementation, only BaseTypes. This would cause events to be omitted. (#1185589)
2. It incorrectly included shadowed events. This would cause either duplicate entries resulting in the same Handles method generation (#530506) or completely invalid entries that would generate invalid code (if the shadowing event uses a different name)

Instead of manually constructing this list of events by navigating around the type hierarchy, we now use LookupSymbols to rely on the compiler's knowledge of what events are available (and which are not available due to shadowing).

Make computation and display of completion item descriptions actually asynchronous.