Add memory-based Read/WriteAsync overloads to SerialStream

[ViktorHofer]

// 'SerialStream' overrides array-based 'ReadAsync' but does not override memory-based 'ReadAsync'. Consider overriding memory-based 'ReadAsync' to improve performance.
// 'SerialStream' overrides array-based 'WriteAsync' but does not override memory-based 'WriteAsync'. Consider overriding memory-based 'WriteAsync' to improve performance.

Disabling the warning in #54544. The overloads should be added to improve performance on .NETCoreApp.

cc @krwq @wfurt @stephentoub

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Issue Details

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// 'SerialStream' overrides array-based 'ReadAsync' but does not override memory-based 'ReadAsync'. Consider overriding memory-based 'ReadAsync' to improve performance.
// 'SerialStream' overrides array-based 'WriteAsync' but does not override memory-based 'WriteAsync'. Consider overriding memory-based 'WriteAsync' to improve performance.

Disabling the warning in #54544. The overloads should be added to improve performance on .NETCoreApp.

cc @krwq @wfurt @stephentoub

Author:	ViktorHofer
Assignees:	-
Labels:	area-System.IO
Milestone:	-

[wcontayon]

Hi @ViktorHofer it's an interesting issue. Can I try a PR ?

[ViktorHofer]

Absolutely. I just assigned you to the issue. Go for it :)

[krwq]

@wcontayon thanks for offering help! Note you'll likely need to do a tiny refactor of code