Add asInteger to numFrames & numChannels of Buffer.alloc & Buffer.getToFloatArray - #7472

fixes #7462

Purpose and Motivation

This PR resolves the error triggered by evaluating the following example code from #7462:

b = Buffer.alloc(s, 6890.625, 10);

// actually, you don't need any data
a = { RecordBuf.ar(Array.fill(10, { WhiteNoise.ar }), b, loop: 0, doneAction: 2); Silent.ar(1) }.play;

b.getToFloatArray(wait: -1, timeout: 10, action: { |data| data.postln });

However, if this example code is not expected to throw an error without truncating 6890.625, then I have misunderstood the issue, and this PR should probably be closed.

As far as I understand it, there are two possible ways to address the issue:

1. Add .asInteger to var count in the getToFloatArray method.
   At the moment, the implementation applies .asInteger to (numFrames * numChannels), which may lead to an incorrect calculation.

2. Add .asInteger to numFrames and numChannels in Buffer.alloc.
   The documentation says that numFrames and numChannels are truncated, but the corresponding method does not currently do this. This commit would make the implementation consistent with the documentation.

I put the second approach in a separate PR (#7471), but my impression is that it is better left as a draft for now. That is why I opened this new PR instead.

Types of changes

• Bug fix

To-do list

• Code is tested
• All tests are passing
• This PR is ready for review