phrasing for OpenCL C extension requirements

[bashbaug]

I've noticed a handful of small issues or possibilities for improvemnent how the OpenCL C specification describes dependencies on OpenCL extensions:

1. The descriptions for the integer dot product functions dot etc. have a line that ends in a comma, for example:

Requires that the __opencl_c_integer_dot_product_input_4x8bit feature macro is defined,

We should figure out whether something else needs to be said here or change the comma to a period.

2. Other extensions use phrasing similar to:

Double-precision floating-point is supported if the cl_khr_fp64 extension macro is supported [...]

In sentences like these do we want to call out the extension macro specifically or should we refer to the extension generally instead, something like "if the cl_khr_fp64_extension is supported"? This shouldn't really matter in practice, since the extension macro will be defined when the extension is supported, but I personally find it more understandable to refer to the extension and not the macro. Note, even if we decide to keep the extension macro text, we may want to say "if the extension macro is defined" rather than "supported".

[bashbaug]

Observed in the April 16th teleconference: there is additional confusion here:

https://registry.khronos.org/OpenCL/specs/3.0-unified/html/OpenCL_C.html#double-precision-support

• There is a trailing comma.
• Need to clarify that fp64 is only supported on OpenCL 1.2 in some cases.
• Double check whether we require the extension macro to be defined when the fp64 extension is supported (regardless of a pragma?).
• Consider exhaustively enumerating all of the cases where the feature is supported - there are quite a few of these!