Fix three errors in BufferPool<bindingType>.

[asuessenbach]

Description

Fixes three errors I introduced with #1091:

• in BufferBlock::allocate(), the C-binding path used the wrong offset;
• the buffer_blocks stored in a BufferPool really need to be pointers to BufferBlocks, as pointers to them are kept in other locations as well; as soon as the BufferBlocks moved due to vector resizing, those pointers were bogus.
• BufferPool::reset() was changed from just reset the BufferBlocks to clear them. But the actual VkBuffers where used to hash the DescriptorSet in RenderFrame::request_descriptor_set. Don't know (for now) hat that works with resetted buffers, but reverted to that code.

Build tested on Win10 with VS2022. Run tested on Win10 with NVidia GPU.

Resolves #1116.

General Checklist:

Please ensure the following points are checked:

• [x] My code follows the coding style
• [x] I have reviewed file licenses
• [x] I have commented any added functions (in line with Doxygen)
• [x] I have commented any code that could be hard to understand
• [x] My changes do not add any new compiler warnings
• [x] My changes do not add any new validation layer errors or warnings
• [x] I have used existing framework/helper functions where possible
• [x] My changes do not add any regressions
• [x] I have tested every sample to ensure everything runs correctly

• [x] This PR describes the scope and expected impact of the changes I am making

  Note: The Samples CI runs a number of checks including:

  • [x] I have updated the header Copyright to reflect the current year (CI build will fail if Copyright is out of date)
  • [ ] My changes build on Windows, Linux, macOS and Android. Otherwise I have documented any exceptions

  If this PR contains framework changes:

  • [ ] I did a full batch run using the batch command line argument to make sure all samples still work properly

Sample Checklist

If your PR contains a new or modified sample, these further checks must be carried out in addition to the General Checklist:

• [ ] I have tested the sample on at least one compliant Vulkan implementation
• [ ] If the sample is vendor-specific, I have tagged it appropriately
• [ ] I have stated on what implementation the sample has been tested so that others can test on different implementations and platforms
• [ ] Any dependent assets have been merged and published in downstream modules
• [ ] For new samples, I have added a paragraph with a summary to the appropriate chapter in the readme of the folder that the sample belongs to e.g. api samples readme
• [ ] For new samples, I have added a tutorial README.md file to guide users through what they need to know to implement code using this feature. For example, see conditional_rendering
• [ ] For new samples, I have added a link to the Antora navigation so that the sample will be listed at the Vulkan documentation site

[gary-sweet]

You probably want to mention the issue number somewhere here to tie this back to it: https://github.com/KhronosGroup/Vulkan-Samples/issues/1116

[gary-sweet]

@asuessenbach I've messaged you privately about the cause of the remaining issue. It would also be really good, since these are framework changes, if you could run batch mode yourself and check the box that prompts you to do so.

[asuessenbach]

It would also be really good, since these are framework changes, if you could run batch mode yourself and check the box that prompts you to do so.

Totally agree. I did run the batch 'til its first failure (which was not related to my changes). Plus some of the other samples, but not all. We should strive to resolve all the failures on every sample!

I've messaged you privately about the cause of the remaining issue.

Thanks a lot for spotting the difference! Will have a look at it right now.

[gary-sweet]

Totally agree. I did run the batch 'til its first failure (which was not related to my changes).

The only thing that was preventing a full batch mode running to completion for me was the bug that this change is addressing. It runs fully for me now, so I'm not sure what other things are broken.

[asuessenbach]

It runs fully for me now, so I'm not sure what other things are broken.

I get an obscure error with hello_triangle (loader_add_layer_properties: 'layers' tag not supported until file version 1.0.1, but C:\Windows\System32\DriverStore\FileRepository\nvdmwi.inf_amd64_5542d7b83d2efdd5\nv-vk64.json is reporting version 1) and a to be fixed error in [hpp_]mesh_shading.