Add optimization for vector conversion of `uint`/`ulong` to `float`/`double`.

[anthonycanino]

AVX512VL adds a number of new packed conversion for unsigned 32-bit/64-bit integer types to float/double. These allow to replace less efficient conversions on xarch --- either multiple instructions or dedicated helper methods --- with single accelerated instructions.

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Issue Details

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AVX512VL adds a number of new packed conversion for unsigned 32-bit/64-bit integer types to float/double. These allow to replace less efficient conversions on xarch --- either multiple instructions or dedicated helper methods --- with single accelerated instructions.

Author:	anthonycanino
Assignees:	-
Labels:	area-System.Numerics
Milestone:	-

[anthonycanino]

Fixed with #84384. Will follow up with an additional PR for some of the remaining cases ,tracked at #80829 and #89279.