In summary this commit:
* drops type normalization in api phase but keeps dealiasing
* fixes#736 and marks corresponding test as passing
I discussed type normalization with @adriaanm and according to him
sbt shouldn't call that method. The purpose of this method to
convert to a form that subtyping algorithm expects. Sbt doesn't need
to call it and it's fairly expensive in some cases.
Dropping type normalization also fixes#726 by not running into
stale cache in Scala compiler problem described in SI-7361.
The infrastructure for resident compilation still exists,
but the actual scalac-side code that was backported is removed.
Future work on using a resident scalac will use that invalidation
code directly from scalac anyway.
While trying to determine binary dependencies sbt lookups class files
corresponding to symbols. It tried to do that for packages and most of the
time would fail because packages don't have corresponding class file
generated. However, in case of case insensitive file system, combined
with special nesting structure you could get spurious dependency.
See added test case for an example of such structure.
The remedy is to never even try to locate class files corresponding to
packages.
Fixes#620.