* dotnet/features/ioperation:
  Fixed unintentional capitalization change.
  Refactors INullCoalescingExpression to ICoalesce expression, and properties to sensible names.

Refactors INullCoalescingExpression to ICoalesce expression, and prop…

* dotnet/features/ioperation:
  Update CSharpReplaceMethodWithPropertyService.cs
  Add VB side of fix.
  Remove unneeded function.
  Improve trivia preservation when converting methods into a property.
  VB side of do-not-simplify-nameof if it changes semantics.
  Do not simplify to an alias in a nameof if it changes the value of hte nameof.
  Include System.Runtime.Serialization.Primitives and System.Security.Cryptography.Csp in PortableFacades CoreXT package. (#21438)
  Address one more refactoring feedback
  Address PR feedback
  Fix possible race conditions in TestExtensionErrorHandler
  Fix expected test results to properly consider trivia
  Improve messages when tests fail due to expected text
  Default to considering trivia during testing
  re-enabled assert we have disabled
  Resolving merge conflict
  Don't pick a project arbitrarily when navigating to symbols

* dotnet/features/ioperation:
  Update CSharpReplaceMethodWithPropertyService.cs
  Add VB side of fix.
  Remove unneeded function.
  Improve trivia preservation when converting methods into a property.
  VB side of do-not-simplify-nameof if it changes semantics.
  Do not simplify to an alias in a nameof if it changes the value of hte nameof.
  Include System.Runtime.Serialization.Primitives and System.Security.Cryptography.Csp in PortableFacades CoreXT package. (#21438)
  Address one more refactoring feedback
  Address PR feedback
  Fix possible race conditions in TestExtensionErrorHandler
  Fix expected test results to properly consider trivia
  Improve messages when tests fail due to expected text
  Default to considering trivia during testing
  Remove RemoveUnneededReferences from LamdaRewriter (#21367)
  Enable embedding sources to Windows PDBs (#21391)
  re-enabled assert we have disabled
  Do not insert Microsoft.DiaSymReader.Native (#21420)
  Resolving merge conflict
  Don't pick a project arbitrarily when navigating to symbols

re-enabled asserts that got disabled before

Expose IsImplicit flag for all IOperation node

Merge master to features/ioperation

Improve trivia preservation when converting methods into a property.

Do not simplify to an alias in a nameof if it changes the value of the nameof

Include System.Runtime.Serialization.Primitives and System.Security.Cryptography.Csp in PortableFacades CoreXT package. (#21438)

Merge pull request #21382 from jasonmalinowski/do-not-pick-project-arbitrarily-for-navigating-to-symbols

Don't pick a project arbitrarily when navigating to symbols

Consider trivia when testing code fixes and refactorings

Merge master to features/ioperation

Currently, the lambda rewriter has an early optimization pass in
analysis that tries to find all local functions that only capture 'this'
and remove references to local functions that do the same. There are two
problems with this approach:

    1) Generally, removing information from the tree is a bad idea
    because it hurts further analysis passes that may have needed that
    information.

    2) The optimization strategy itself is very tricky and has a number
    of complex corner cases. This has lead to bugs, for example #19033.

This PR deletes the current method and adds a new optimization routine
at the end of the analysis, operating on assigned scopes and
environments rather than removing captured variable analysis. The new
optimization is as follows: if we end up with an environment containing
only 'this', the environment can be removed, all containing methods can
be moved to the top-level type, and all environments which capture the
'this' environment can instead directly capture the 'this' parameter.
This produces almost the same results as the previous optimization, but
is easier to validate as an algebraic equivalence.

The baseline changes come from the new optimization being less aggressive 
about moving functions which only capture 'this' to the top level. This
appears to be a wash -- some codegen gets slightly better, some gets
slightly worse.

Fixes #19033
Fixes #20577

* Compare lines instead of using AssertXml when validating PDBs.

AssertXml doesn't validate ordering.

* Reorder expected PDB XML nodes to match actual order

* Update to the latest Microsoft.DiaSymReader.* packages.

* Enable embedding sources to Windows PDBs

Merge master to features/ioperation

Merge remote-tracking branch 'upstream/master' into merges/master-to-features/ioperation-20170810-070014

Merge master to features/ioperation

Recommend 'case' keyword after a pattern-case-clause.

Trim the length of the banner that we show for outlining down a bit.