[code-reflection] RFR: [hat] ComputeRange and ThreadMesh API for defining 1D, 2D and 3D Ranges [v2]

[Juan Fumero]

> This PR proposes an extension of the HAT API to leverage 1D, 2D and 3D ranges for the compute context dispatch. 
> A `ComputeRange` is an entity that holds global and local thread mesh. In the future, we can add offsets to it. 
> 
> Each `ThreadMesh` is a triplet representing the number of threads for x,y, and z dimensions. 
> 
> How to dispatch 1D kernels?
> 
> 
> ComputeRange range1D = new ComputeRange(new ThreadMesh(size));
> cc.dispatchKernel(computeRange,
>                 kc -> myKernel(...));
> 
> 
> How to dispatch 2D kernels?
> 
> 
> ComputeRange range2D = new ComputeRange(new ThreadMesh(size, size));
> cc.dispatchKernel(computeRange,
>                 kc -> my2DKernel(...));
> 
> 
> How to enable local mesh? 
> 
> We pass a second parameter to the ComputeRange constructor to define local mesh. If it is not passed, then it is `null` and the HAT runtime can select a default set of values. 
> 
> 
> ComputeRange computeRange = new ComputeRange(
>         new ThreadMesh(globalSize, globalSize), 
>         new ThreadMesh(16, 16));
> cc.dispatchKernel(computeRange,
>                 kc -> matrixMultiplyKernel2D(kc, matrixA, matrixB, matrixC, globalSize)
>         );
> 
> 
> In addition, this PR renames the `KernelContext` internal API to map the context ndrange object to native memory to `KernelBufferContext`.
> 
> 
> #### How to check? 
> 
> 
> java @hat/run ffi-opencl matmul 1D
> java @hat/run ffi-opencl matmul 2D
> 
> java @hat/run ffi-cuda matmul 1D
> java @hat/run ffi-cuda matmul 2D

Juan Fumero has updated the pull request incrementally with one additional commit since the last revision:

  minor change

-------------

Changes:
  - all: https://git.openjdk.org/babylon/pull/515/files
  - new: https://git.openjdk.org/babylon/pull/515/files/257ff1de..51efd2c2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=515&range=01
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=515&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/babylon/pull/515.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/515/head:pull/515

PR: https://git.openjdk.org/babylon/pull/515