[SYCL][COMPAT][cuda] Add "ptr_to_integer" syclcompat functions.

[JackAKirk]

Add "ptr_to_integer" (generic address space to .shared) syclcompat functions.

These functions are commonly required in optimized libraries that use inline ptx. The standard naming convention of removing "__" from corresponding cuda builtins has been applied. See the readme and accompanying test-e2e for example usage.

[joeatodd]

Since these functions do the same thing aside from casting to int/size_t, can we not implement them as a single templated function?

[JackAKirk]

Since these functions do the same thing aside from casting to int/size_t, can we not implement them as a single templated function?

Uncertainty around this is the reason I put them in experimental. It's a bit messy since the cuda versions of these api require different cuda toolkit versions (10.1 for the uint32_t and 11 for size_t, I think), but this does not affect these syclcompat translated versions. I was just told to translate them in this way so that cutlass sycl path can have corresponding apis to cuda runtime path. I don't think I really have the context to make a decision beyond this. It is probably best to ask @aacostadiaz what is best.

[JackAKirk]

Since these functions do the same thing aside from casting to int/size_t, can we not implement them as a single templated function?

@aacostadiaz wants them to be two separate functions, so I'll leave it as it is.

[JackAKirk]

@Alcpz @joeatodd Any more reviews for this?

Thanks

[joeatodd]

As discussed offline, these should be a single function with a template parameter describing the return type.

[npmiller]

Closing this after further discussions offline