Rename files and directories before merge with HPVM

hpvm/include/GenHPVM/GenHPVM.h

hpvm/include/SupportHPVM/DFG2LLVM.h

hpvm/include/SupportHPVM/DFGTreeTraversal.h

hpvm/include/SupportHPVM/DFGraph.h

hpvm/include/SupportHPVM/HPVMHint.h

hpvm/include/SupportHPVM/HPVMTimer.h

hpvm/include/SupportHPVM/HPVMUtils.h

hpvm/lib/Transforms/DFG2LLVM_CPU/CMakeLists.txt

hpvm/lib/Transforms/DFG2LLVM_CPU/DFG2LLVM_CPU.cpp

hpvm/lib/Transforms/DFG2LLVM_CPU/DFG2LLVM_CPU.exports

hpvm/lib/Transforms/DFG2LLVM_CPU/LLVMBuild.txt

hpvm/lib/Transforms/DFG2LLVM_OpenCL/CMakeLists.txt

hpvm/lib/Transforms/DFG2LLVM_OpenCL/DFG2LLVM_OpenCL.cpp

hpvm/lib/Transforms/DFG2LLVM_OpenCL/DFG2LLVM_OpenCL.exports

hpvm/lib/Transforms/DFG2LLVM_OpenCL/LLVMBuild.txt