[Hexagon] Add Hexagon-specific loop idiom recognition pass

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293213 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Krzysztof Parzyszek

lib/Target/Hexagon/CMakeLists.txt

@@ -35,6 +35,7 @@ add_llvm_target(HexagonCodeGen
   HexagonInstrInfo.cpp
   HexagonISelDAGToDAG.cpp
   HexagonISelLowering.cpp
+  HexagonLoopIdiomRecognition.cpp
   HexagonMachineFunctionInfo.cpp
   HexagonMachineScheduler.cpp
   HexagonMCInstLower.cpp