`f16b` Primitive Type

[nxsaken]

Metadata
Point of contact	@Jamesbarford
Team(s)	compiler, lang
Goal document	2026/bf16

Summary

Implementation of a f16b type in core::num for the 16-bit
Brain Floating Point format.

Tasks and status

[nxsaken]

This issue is intended for status updates only.

For general questions or comments, please contact the owner(s) directly.

[Jamesbarford]

• f16b Implementation PR Is in review by @folkertdev, with the review comments are being addressed. Pipeline is green.
• f16b RFC Is in review, with one outstanding item namely; "commit-to-no-other-bf16". Clarity is needed on whether the presently stated point about core::arch::x86::bf16 using f16b is enough to satisfy this outstanding item.