[HIPIFY] Introduce CUDA installation path option '-cuda-path'

Repeats clang's '--cuda-path' option.

[Reason]
In case of absence of any other clang's options setting '-cuda-path' allows not to specify separator '--' before clang's '--cuda-path'.

+ Tests and scripts are updated accordingly.

hipify-clang/src/ArgParse.h

@@ -32,6 +32,7 @@ extern cl::OptionCategory ToolTemplateCategory;
 extern cl::opt<std::string> OutputFilename;
 extern cl::opt<std::string> OutputDir;
 extern cl::opt<std::string> TemporaryDir;
+extern cl::opt<std::string> CudaPath;
 extern cl::opt<bool> Inplace;
 extern cl::opt<bool> SaveTemps;
 extern cl::opt<bool> NoBackup;