Fixes #14895

Fixes #5072.
Also fixed some issues around LangVersion handling, which were found along the way.

1. CompilationWithAnalyzers can now report analyzer diagnostics with source suppressions (pragma/SuppressMessageAttribute). This will eventually allow us to surface diagnostics with source suppressions in the error list. Note that the behavior of command line compilers and all the GetDiagnostics APIs is unchanged, only the compiler analyzer will report diagnostics with source suppressions.

2. Add FixAll support for Suppression code fixes. Light bulb suppression fixes now show the "Fix all occurrences" options for Document/Project/Solution. This change adds the basic functionality to bulk suppress diagnostics. This will eventually be consumed for baselining all/selected diagnostics from error list/solution explorer.

3. Simplify the Suppression light bulb menu to remove the option to add a local SuppressMessageAttribute. The only options now are to suppress in source (pragma) or suppressions file (assembly level SuppressMessageAttribute).

Fixes #4924.

Fixes #2604.

Fixed #2424.

Now that the comment formatting issue is fixed in the Formatter type, we can run the formatter on the remainder of the VB code base.

closes #1424

Fix #409:
Add explicit StringComparison.Ordinal or StringComparison.OrdinalIgnoreCase where it was intended,
or replace single-char string literals with chars literals.
Also, provide InvariantCulture in TryParse where it was intended.

Use AssertTheseEmitDiagnostics instead of compilation.VerifyEmitDiagnostics to keep the orignal baseline form.

These checks were required for some VB tests, not for product code.
By updating VB tests, we can remove them and simplify the lowering phase.

VB: Adjust logic used to decide whether InternalXmlHelper class is going to be embedded into a compilation.

Rather than checking names of referenced assemblies, compiler explicitly checks for availability of types the implementation of InternalXmlHelper depends upon. These are the types explicitly referenced by the code:
System.Linq.Enumerable,
System.Xml.Linq.XElement,
System.Xml.Linq.XName,
System.Xml.Linq.XAttribute,
System.Xml.Linq.XNamespace.

This adjustment should enable usage of XML literals while targeting PrjectN and similar framework flavors.

For the purpose of the check, the type is considered available if an accessible type with the required name is declared in at least one of the referenced assembly.

***NO_CI***
 (changeset 1401127)

As in the original C# implementation of Color Color handling, the Color Color handling in the VB binder originally used lookup to decide the meaning of an ambiguous identifier as a simple name or type name instead of binding.

Unfortunately, this is not correct: the meaning of an identifier as outlined in the spec is defined by binding. This caused the compiler to incorrectly fail to recognize Color Color in situations where a simple name or type name lookup is ambiguous but a bind of the same is not. This change replaces the lookups used in Color Color with binds, which brings Roslyn's behavior back in line with Dev12 and the spec in cases that fit such cases.

This change is likely to be slightly perf-positive in cases involving a simple name that does not bind to a symbol that qualifies for the Color Color rule: in this case, the old code performed a lookup followed by a bind, whereas the new code simply performs a bind and returns the result. There is likely to be a perf penalty in a true Color Color case, however, as the bound node is larger and the new code is unconditionally binding the type even in the case where the type will not be used (whereas the old code would simply look up the type).
***NO_CI***
 (changeset 1401089)

 Make tests passing on a non-English OS, even in presence of corresponding localized resources. In the process several product issues were fixed like:
     - Localized exception messages incorporated into diagnostics by command line compiler are not obeying /preferreduilang switch.
     - Some strings are loaded from resources at the time when diagnostic object is created. Resources are loaded earlier than they could be. When error message is requested, it might not be localized in accordance with the requested culture.
     - When target culture is not provided, DiagnosticInfo objects used as arguments within another diagnostic object are formatted using InvariantCulture, whereas all other arguments use current culture (as expected). Portions of the message are localized to different languages. (changeset 1392630)

IsDefinedOrImplementedInSourceTree – when called for an implicitly declared instance constructor, return the answer for the containing type. This ensures that an error about missing parameter-less base constructor is returned for syntax tree containing declaration of a derived type. (changeset 1378066)

Improve informativity of diagnostics about overload resolution failure due to an ambiguity. Fixes #364. (changeset 1371395)

VB: Overloadable members from unrelated interfaces should no longer trigger an ambiguous lookup error. Fixes #34. (changeset 1360454)

***NO_CI***
 (changeset 1356181)

CR feedback on the allowing assigning to readonly properties in constructors change. (changeset 1351156)

Abbreviates the public VB-specific types (e.g. VisualBasicSyntaxTree -> VBSyntaxTree) in accordance with the .NET Class Library Guidelines to avoid overly lengthy names and consistent with the conventions used in other APIs (e.g. VB CodeDom). (changeset 1348499)

Simply the VB syntax trees for single- and multi-line Ifs and Try blocks, making them consistent with the VB language spec.

Now, instead of being parented by an intermediate "If Part" or "Try Part" the header statements and the body statements are directly parented by the block (similar to how we represent them in C#). (changeset 1348193)

made compiler error message to not include namespaces in most cases. this should make parsing error message a bit easier. (changeset 1334448)

Stop validating warning ids specified in /nowarn and /warnaserror and allow custom diagnostics to be specified via both (in both VB and C#).

Also, start reporting custom info diagnostics on the command line. The compiler generated info diagnostics for unused imports have now been changed to 'hidden' so that we don't start seeing them all over the place during builds. (changeset 1315557)

lll
mmm
nnn
unecessary
targetting/targetted
copmilation
egnine
collecton
appropreate
dignostic
diagostic
the a / a the
the the/ a a (changeset 1294596)

     lamda
     compilaton
     compatable/incompatability
     warings
     retrun
     converion
     delagate
     buid
     namepsace (changeset 1290811)

rcsc to csc
rcsi to csi
rcsc2 to csc2
rvbc to vbc
rvbi to vbi
rvbc2 to vbc2
 (changeset 1285266)

Bug Fix and cleanup for VB Squiggle location for Unimplemented Interface Method diagnostic - C# was already fixed as part of Bug 911913

Cleanup (Based upon some items raised in C# implementation code review)
-remove unused code
-change name to match C# implementation (Interface rather than iFace) (changeset 1252243)

Additional test coverage for BC41000 warning generated but roslyn intentionally does not.      (changeset 1225515)