This patch refactors the definition of common utility function "isInductionPHI" to LoopUtils.cpp.
This fixes compilation error when configured with -DBUILD_SHARED_LIBS=ON
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235577 91177308-0d34-0410-b5e6-96231b3b80d8