Merge 2.10.x into master.

Fix check file for run/t7185.
No-op merge for [nomaster] part of 2.10.x.
Merge 2.10.x into master.

Conflicts:
	src/compiler/scala/tools/nsc/transform/Erasure.scala
Merge 2.10.x into master.

Conflicts:
	src/library/scala/collection/mutable/ArrayOps.scala
Merge 2.10.x into master.

Conflicts:
	src/compiler/scala/tools/nsc/transform/patmat/Logic.scala
Merge 2.10.x into master.

Resurrect some undead code from 373ded2ad3 (tuple2Pickler).

Conflicts:
	src/compiler/scala/tools/nsc/interactive/CompilerControl.scala
	src/compiler/scala/tools/nsc/typechecker/Typers.scala