Fix the limitation of supported input files.
Fix the limitation of supported input files.

Actually .cu and .cuda was supported.

+ All the file names are allowed, including file names without extension.

[IMPORTANT]
To hipify CUDA input file, which name is not *.cu, please add option "-x cuda" after tool's options ending marker "--", for instance:

./hipify-clang NeuralNet -- -x cuda

This option will go to clang itself, not the hipify tool.

GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP,ROCm-Developer-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,GPUOpen-ProfessionalCompute-Tools/HIP,ROCm-Developer-Tools/HIP