Also convert tabs to spaces in the switch tests.

This change increases the severity of analyzer exception diagnostic (AD0001), generated when an analyzer throws an exception, from info to a warning. Additionally, its descriptor is now reported as a supported diagnostic descriptor of the compiler analyzer, which ensures that it shows up in the ruleset editor.

Fixes #3707

Test EmitSeuqnceOfBinaryExpressions_03 is failing the stabilization and master
signed builds. Tracked by bug #6077

(cherry picked from commit 8a24f90b)

Test EmitSeuqnceOfBinaryExpressions_03 is failing the stabilization and master
signed builds. Tracked by bug #6077

SynthesizedParameterSymbol.DeriveParameters should preserve order between custom modifiers and ByRef modifier.

Fixes #5993.

Added tests for switch, foreach.

They are no longer needed.  Time to remove them.

Added support and tests for lambdas and local functions, but it doesn't work so tests are skipped.

...and update namespaces contained therein accordingly.

Csc and Csi are portable projects targeting 5.0 portable
without support clauses, this confuses portable as it
doesn't know the projects target and warns when they
reference other portable projects.

This also enables package validation to ensure that these
projects will never reference a package that doesn't work
on its given targets.

This change adds a ShebangDirectiveTriviaSyntax type to the public API.

AppConfigBasicFail fails at home because I have an "I" drive
that is plugged in. Change it to use an existent drive, so the
drive is connected, but the path just can't be found.

Fixes #6079

Fixes #949

Fixes #6040.

And update project.lock.json

It's not guaranteed.

Fixes #5927

Fixes #4221

Fixes #2544.