Add support to TornadoNativeArray data types to get Memory Segments without header offset

[mikepapadim]

Description

This PR adds support to obtain a MemorySegment from TornadoNativeArray types with and without the header bytes.

• MemorySegment getSegment() returns a memory segment excluding the Tornado header.
• MemorySegment getSegmentWithHeader() returns a memory segment as allocated for TornadoVM including the Tornado header (24bytes).
• long getNumBytesOfSegmentWithHeader() returns Segment's number of bytes including the Tornado header.
• long getNumBytesOfSegment() returns Segment's number of bytes excluding the Tornado header.

By having distinct funtion in the above auxiliry methods we can have interoperoability when using Segments for GPU execution through the Taskgraph API and Vector API when using any of the TornadoNative types.

Also, refactor internally methods that operate on memory segments to be named explictly as getSegmentWithHeader.

Backend/s tested

Mark the backends affected by this PR.

• [x] OpenCL
• [x] PTX
• [x] SPIRV

OS tested

Mark the OS where this PR is tested.

• [x] Linux
• [ ] OSx
• [ ] Windows

Did you check on FPGAs?

If it is applicable, check your changes on FPGAs.

• [ ] Yes
• [x] No

How to test the new patch?

make jdk21  BACKEND=openc
make tests 

---

[jjfumero]

I am confused. The withHeader version, does it always return +24 bytes, or it returns the bytes specified in TornadoNativeArray.ARRAY_HEADER?

[mikepapadim]

I am confused. The withHeader version, does it always return +24 bytes, or it returns the bytes specified in TornadoNativeArray.ARRAY_HEADER?

withHeader returns always number of bytes including the TornadoNativeArray.ARRAY_HEADER

[jjfumero]

I am confused. The withHeader version, does it always return +24 bytes, or it returns the bytes specified in TornadoNativeArray.ARRAY_HEADER?

withHeader returns always number of bytes including the TornadoNativeArray.ARRAY_HEADER

So please, update the PR description with this.

[mikepapadim]

I am confused. The withHeader version, does it always return +24 bytes, or it returns the bytes specified in TornadoNativeArray.ARRAY_HEADER?

withHeader returns always number of bytes including the TornadoNativeArray.ARRAY_HEADER

So please, update the PR description with this.

done

[jjfumero]

Unittests are passing on OSx 14.4

[mikepapadim]

@jjfumero done

[jjfumero]

ok, thanks. the PR looks good to me.