Rewrite the handling for the `CxxStdlib` implicit linking to use a
slightly more functional style for filtering. Additionally, add Windows
to the list providing the overlay. The Windows linking scenario is a
slightly more complicated as the library names differ between static and
dynamic variants to disambiguate between import libraries and static
libraries. Take this into account when embedding the library name so
that the linker can find the appropriate content.
This patch to the Clang Importer avoids an assert by detecting when an
IndirectField belongs to an anonymous union that is not importable. How
it does this is by determining if an IndirectFieldDecl's anonymous
parent field is non-importable (based on isCxxRecordImportable) and if
so skips importing the IndirectFieldDecl.
This avoids the mentioned assert because makeIndirectFieldAccessors
expects a FieldDecl of __Unnamed_union___Anonymous_field that is only
populated when the top-level union is imported from an
IndirectFieldDecl's parent. IndirectFieldDecls for the members of an
anonymous union are dependent on their parent and should not be imported
if their parent can not also be imported.
This corner case can happen in cases when an anonymous union contains an
ARC pointer, which results in a non-trivial but also inaccessible dtor.
