compiler: change expression importing to use Import_expression
Change expression importing to use a new abstract interface class
Import_expression, so that we can more easily import expressions from
inlinable function bodies. This is a refactoring with no affect on
compiler behavior.
Change-Id: I9178ad6b2272f9abad540576fcff72a746d1e5bc
Reviewed-on: https://go-review.googlesource.com/c/150065
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
6 files changed
