* dotnet/master:
  made NFW to bucket things better (#22865)
  Reverted IsImplicit to original code to be able to handle lowered bound trees in the future.
  added completion set and fix all telemetry to track performance (#22811)
  porting named pipe fix from service hub. (#22863)
  remove duplicated reference in the test (#22787)
  Remove IConversionExpression.IsExplicitInCode
  When creating child items in Call Hierarchy, use the correct project
  Make tests easier to diagnose if the fail
  Remove duplicate test helpers and put overloads right next to each other
  Remove duplicate project references.
  Update the summaries and descriptions of these packages to not be wrong
  Remove exact version requirements in our Razor NuGet packages

* made NFW to bucket things better

NFW API allows caller to supply extra info to make bucketting better.

this takes advantage of that ability for certain exception types which we know inner or remote exception is more important than the generic outter exception.

* added more comments

Remove IConversionExpression.IsExplicitInCode

* dotnet/master: (21 commits)
  added completion set and fix all telemetry to track performance (#22811)
  porting named pipe fix from service hub. (#22863)
  remove duplicated reference in the test (#22787)
  Fix unit test failures from merge resolution
  fixed regression on using nuget (#22809)
  Fix few more doc comments
  When creating child items in Call Hierarchy, use the correct project
  Make tests easier to diagnose if the fail
  Remove duplicate test helpers and put overloads right next to each other
  Remove duplicate project references.
  Fixed some doc comments
  Address review feedback and remove IsExpression and IsStatement properties.
  Address more feedback from design meeting and expose IOperation.IsExpression and IOperation.IsStatement properties
  Namespace change for IOperation APIs
  Fix unit test
  Unit test changes for IOperation API changes
  Update the summaries and descriptions of these packages to not be wrong
  Remove exact version requirements in our Razor NuGet packages
  Test framework changes for IOperation API changes
  Fix IDE analyzers for IOperation API changes
  ...

Refactor ISingle and IMulti to IVariableDeclarator and IVariableDeclaration, to match syntax terms and be less confusing.

Remove exact version requirements in our Razor NuGet packages

Remove duplicate project references.

* added time tracking to completion set.

from the point we start completion set to first time we are called from VS for best match (which indicate that completion set is actually shown to users first time for this particular completion session)

the event is vs/ide/vbcs/intellisense/completion

if completion is done without showing UI to users (etc or tab), then event will be marked as cancelled.

* added perf tracking to LB fix all.

there were already existing events so I just made those to include perf info (duration) as well.

among all those events, these 2 are ones we were planning to add

vs/ide/vbcs/codefixes/fixalloccurrencescomputation
this shows time from the point user invoked fix all to where we shows preview window to users.

vs/ide/vbcs/codefixes/applychanges
this shows time from user clicked Apply from preview window to where we actually applied the changes to VS

there are more events between them in case we want to dig in details later such as how long it took to calculate diagnostics, how many files are affected and etc.

also all related events have correlation id to group related code fix events. also for fix all case, it contains scope to show whether fix all is for document, project, solution.

* PR feedback. removed unnecessary parameter

* removed repeated correction id set

* updated comments.

* dotnet/master:
  Fix unit test failures from merge resolution
  fixed regression on using nuget (#22809)
  Fix few more doc comments
  Add regression tests for IOperation. (#22837)
  Add description for compiler packages that are pre-release (#22777)
  Fixed some doc comments
  Address review feedback and remove IsExpression and IsStatement properties.
  Bump package versions for Preview 3
  Address more feedback from design meeting and expose IOperation.IsExpression and IOperation.IsStatement properties
  Update VB ObsoleteAttributeData to use the same implementation as C#
  Only check for missing attributes when we know the syntax tree is available
  Namespace change for IOperation APIs
  Fix unit test
  Unit test changes for IOperation API changes
  Test framework changes for IOperation API changes
  Fix IDE analyzers for IOperation API changes
  Rename IOperation APIs as per the new API design principles:
  merge fix
  reverted IConditionalAccessExpression change
  fixed documentation spelling

When creating child items in Call Hierarchy, use the correct project

while investigating NFW issue, service hub team found a bug in NamedPipe library code. I am porting that fix to our side since we use same code for named pipe.

this is service hub PR (https://devdiv.visualstudio.com/DevDiv/Connected%20Experience/_git/DevCore/pullrequest/91111?_a=overview )

Operations API rename/refactor

Refactored BoundLocalDeclaration to have separate initializers for Array bounds and the standard declaration.

looks like I broke it when I did refactoring on KeepAliveSession by giving in wrong callback object.

fix https://github.com/dotnet/roslyn/issues/22806

opened this for adding unit test - https://github.com/dotnet/roslyn/issues/22808

currently we don't have test around ISymbolSearchService.

fixed documentation spelling

Closes #7582.

Call Hierarchy items hold onto their project so we can relocate the
symbol, but instead of using the project that contained the caller, we
were creating items with the project of the original method. This meant
that further expansions wouldn't work correctly.

Merge dev15.4.x to master

Bump package versions for Preview 3

* dotnet/master:
  Address a number of IOperation issues for VB (#22795)
  Ensire that IOperation nodes representing param arrays and default values are properly marked as implicit. (#22758)
  Verify symbol
  Update AssertEx.SetEquals to print better output
  Add a test to ensure search after an edit actually works
  Allow null MethodGroup.Receiver in error cases
  Report non-fatal exception telemetry if we have an issue
  Guard against the project being removed
  Don't have AbstractCallFinders hold onto projects
  Don't use Assert.True if we have a better assertion
  Ensure we always complete the call hierarchy search
  Avoid leaking documents if an exception is thrown in AddDocument
  Convert unreachable code analyzer to a semantic model analyzer