This reverts commit 27dc60f5.

* 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

Enable few more rules and fix issues identified these rules.

Also added issue IDs for the disabled rules due to lack of a fixer/fix all experience.

The PDB path which is written into the PE file should respect the
`/pathmap` option passed to the compiler.  This is necessary to ensure
that PEs can be deterministic when built from different source paths.

The feature flag `pdb-path-determinism` is being kept for the time
being.  Even though it's a feature flag it still seems inappropriate to
break customers in a point release.  Deferring the removal until the
next major release to give customers time to react.  This issue tracks
removing the flag:

https://github.com/dotnet/roslyn/issues/19592

closes #9813

* Ref assemblies make a best effort to emit with determinism
* Fixing CopyRefAssembly message output
* CopyRefAssembly logs when input isn't ref assembly
* CopyRefAssembly does assembly redirect.
* Compact error codes for C# 7.1

* refonly and refout on command-line and msbuild
* corresponding change to Emit API
* Metadata-only assembly use `throw null` bodies
* Can no longer produce netmodule with metadata only

* remove no-arg-constructors for ArgumentException from compiler

* fix all `new ArgumentException(nameof(paramname))` instances.

* update error

Fixes #10023.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems?id=233669.

Fixes #14365.

Fixes https://devdiv.visualstudio.com/DevDiv/_workitems?id=217718.

Provide an API to get unreferenced assembly identities obects from the diagnostics reported about them.

Use tuple syntax in the compiler

Support setting if an anonymous type's properties are mutable or not.

* CommonPEModuleBuilder refactoring

* Renames

* Use CommonPEModuleBuilder instead of IModule

* Remove IModule

* Move GetFiles to module builder

* Remove IAssembly

* Add comments, PR feedback

* Resolve merge conflicts