[PATCH] [Polly][Unfinished][NFC] Restructure the command line options

[Johannes Doerfert]

>>! In D5762#5, @simbuerg wrote:
> Maybe I'm old, but the only benefits I see here are the external linkage via Options.h and the consistent naming, no need for relocating the definitions too.
I find myself more often than I like looking for command line options to control something. I want to know the command line name and the default value, however that's not that easy:
  Do you know where SCEVCodegen is declared, how to enable OpenMP code generation or what option will disable runtime alias checks?
These are some of the options that have a non-local effect; thus you might not find in the command line option declaration in the files you'd expect.

If you are interested in the effect of the internal command line option variable you will still see the same as before if you only open your pass. If the option variables are namend properly you don't need to look at the command line option declaration to understand the code.

```
if (PollyEnableTiling)
  XXX
```

I do not insist on this change, if others have the same objections or you feel realy strongly about this I don't mind take that part back. But in general I still think it will clean up Polly and help us.

[btw. SCEVCodegen -> BlockGenerators.cpp, OpenMP -> CodeGeneration.cpp, RTCs -> ScopDetection.cpp]

http://reviews.llvm.org/D5762