* Clean up string resources, use Arcade resx generator

* CodeLens resources


* Use NET20 instead of NETFX20

* Permit tests that fail certain assertions to run in Release builds
See #25702 for details.

This updates our duplicate reference check to compare names in addition
to reference identity. This found ~600 tests which were inadvertently
passing duplicate references to our compilation helpers.

closes #25509

- Added some improved debug-time display for synthesized locals
- Added some invariant checking regarding bound nodes.
- Move invocation of the spiller into LocalRewriter.Rewrite
- Add an error for when an expression tree contains a switch expression
- Made the local substituter apply at the top level in the expression spiller because expressions can now contain statements (BoundSpillSequence)
- Move the error ERR_ByRefTypeAndAwait to IteratorAndAsyncCaptureWalker
- Skip broken tests due to #25702

Both compilers are able to represent ByRef returns without this special symbol.

This reverts commit bb509134. We need to investigate intermittent failures in DiaSymReader first.

Fell out of our normal cadence for this during the push for RTM. Now that we
had a bit more breathing room getting us back on track here.

Unskip the ones associated with closed bugs and make sure the others are
clearly labelled.

Move aliases out of ```EvaluationContext``` so that they don't interfere with our caching strategy.

Clean up the overall diff.

1) Instead of asking for the type of an individual alias to determine if
it exists in the current context, ask for a list of all aliases up front.

2) Include aliases in the result of CompileGetLocals (so that the debugger
no longer has to partially populate the window).

Bonus: Fixes #878.

In Windows 8 (and 8.1), runtime winmds may contain assembly refs pointing
to other runtime winmds (for example, types defined in Windows.UI.Xaml
point to Windows.UI).  However, when the EE sees these assembly refs it
must redirect them back to the compile time contract assembly (Windows),
because the Compilation used by the EE only references the contract Assembly,
not the various runtime Assemblies.  Previously, we only did this redirection
for Windows 10.  Non-EE cases should only see the contract assembly at
compile time, so this change will not affect them.

We used to have multiple mechanisms - constructing a co-class directly
from a registered GUID, wrapping the co-class in SymReader (for some extra
constant mocking), wrapping the co-class in a TempPdbReader (IDisposable),
and wrapping a TempPdbReader in a DebugInfoProvider (trivial wrapper).

This change eliminates TempPdbReader and DebugInfoProvider and gives
SymReader exclusive access to the raw co-class.

This will be useful when we switch to ISymUnmanagedReader3, which the
co-class does not presently implement (but which SymReader can).