JvmPackagePartProvider should not just blindly load all multifile parts from
all libraries on the classpath, but only those from multifile classes which
shadow (come earlier on the classpath) other classes with the same name.
Otherwise if you have different versions of the same library (which uses
multifile classes) on the classpath, the compiler will see parts from both
versions. If some declaration have moved from one part to another, it's
possible to observe an overload resolution ambiguity error
#KT-15287 Fixed
Alexander Udalov
7b5c90ebaf