Revisit the optimization that provides a fast path for instances of
`NSError` when erasing the `Error` type in `emitExistentialErasure`. It
generated references to `NSError` when the `Foundation` module was
loaded, no matter how it was imported. This lead to deserialization
failures at reading the swiftmodule when that reference was added to
inlinable code while `Foundation` was not a public dependency.
Fix this crash by limiting the optimization to all non-inlinable code
and only inlinable code from a module with a public dependency on
`Foundation`. This is the similar check we apply to user written
inlinable code, however here we use the module-wide dependency instead
of per file imports.
rdar://142438679
