Rename the unittest from ArrayRecylerTest.cpp to ArrayRecyclerTest.cpp.

Fixes the CMake build. It took me cutting and pasting this before
I managed to see the missing character. =]
Sink the AddressingModeMatcher helper class into an anonymous namespace
next to its only user. This helper relies on TargetLowering information
that shouldn't be generally used throughout the Transfoms library, and
so it made little sense as a generic utility.

This also consolidates the file where we need to remove the remaining
uses of TargetLowering in favor of the IR-layer abstract interface in
TargetTransformInfo.