With Zfinx, Zdinx, Zhinx, and Zhinxmin there's a clear precedent that
floating point extensions should have an analogous "inx" version. As
defining such a variant is straight-forward, I feel it would be most
sensible (and efficient) to define it as part of the bfloat16 definition
process rather than leaving a gap within the ISA to be filled at a later
date.

This drafts such a definition. As the bfloat16 extensions are defined in
new documentation rather than patches to the riscv-isa-manual, I've
duplicated some explanatory text from the Zfinx chapater of the manual
so that the zfbfinxmin definition makes sense standalone. If merging
into the ISA manual, it would of course take a different form.

Signed-off-by: Rafael Sene <rafael@riscv.org>

Some changes are mid-process.

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

Updating the date and rev for the next build

These instructions were recently added to zvbfwma (as opposed to having
a dependency on zfh or zfhmin), but the insns/*.adoc files weren't
updated to reflect this.

Added FLH and FSH to the Zvfbfwma extension to enable the load/store of scalar elements as needed by the vector-scalar form of the instruction.

vfwbulb16.adoc had previously been removed from specification

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

Removing the requirement that this be built on  top of FP16. Instead, we are including the storage and move instructions from those extensions.

Removing vfwmulb16 (leaving vfmaccbf16)
Moving towards dropping the Zfhmin requirement and instead adding  FLH, FSH, FMV.X.H, and FMV.H.X as part of the specification.

Added dependencies on Zfhmin or Zfh.
Testing attributes in encodings (fcvt_BF16_S)

Signed-off-by: Ken Dockser <37552326+kdockser@users.noreply.github.com>
Co-authored-by: Ken Dockser <37552326+kdockser@users.noreply.github.com>

This is a minor editorial fix.

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>
Signed-off-by: Ken Dockser <37552326+kdockser@users.noreply.github.com>
Co-authored-by: Ken Dockser <37552326+kdockser@users.noreply.github.com>

* register syntax in vfwmaccbf16

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

* Update vfwmulbf16.adoc

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

* Update vfwcvtbf16_f_f_v.adoc

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

---------

Signed-off-by: Nicolas Brunie <82109999+nibrunieAtSi5@users.noreply.github.com>

v2 ==> v3

"Add 22.04 dependencies": https://github.com/riscv-non-isa/riscv-iommu/commit/bbef16fcbe26fc0b3797e3728d6df2ef4ea63c36

Restored the extension name back to Zfbfmin