Explicit imports should always conflict with local declarations using
the same name. Wildcard imports only conflict if they are referenced
before a local declaration with the same name.
This also unifies the detection of identifier conflicts.
Rework lexical support for PACKAGE_IDENTIFIER so that the lexor
can help with package scoped identifiers.
Pform package types and package functions up to elaboration.
This was temporarily implemented to just copy definitions to the
local scope, but the better method is to create a PEIdent that has
the package attached to it.
Martin Whitaker
Stephen Williams