Merge remote-tracking branch 'origin/2.10.x' into pr/merge-2.10

* origin/2.10.x:
  SI-6969, mishandling of SoftReferences in method cache.
  SI-7011 Fix finding constructor type in captured var definitions
  SI-6987 Tests fsc verbose output
  SI-6987 Fixes fsc compile server verbose output
  SI-6231 Report unsupported free var capture by a trait.
  SI-6666 Restrict hidden `this` access in self/super calls.
  SI-6902 Check unreachability under @unchecked
  SI-6976 Fix value class separate compilation crasher.
  Closes SI-6952: add correct error positions for Dynamic feature check.

Conflicts:
	src/compiler/scala/tools/nsc/CompileServer.scala
	src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala