very nice, careful work!

i have a bunch of refinements below, and also updates to other parts of the spec

14.4.5

"The storage and uniform address spaces have different buffer layout constraints which are described in this section."

Replace "buffer" with "memory" ?? Or delete "buffer" entirely?

14.4

"AlignOf(T) is the alignment of T", when T is not a a buffer type.

14.4 AccessibleBytes

AccessibleBytes(T) is not defined otherwise. (other than the listed cases)

14.4.1 Alignment and size.

"Each host-shareable or fixed footprint data type T has an alignment and size."

Suggest splitting cases, to make the exception clear:

Each host-shareable or fixed footprint type has a size.

Except for [=buffer=] types, each host-shareable or fixed footprint type has an alignment.

14.4.4 Internal layout of values.

"These layouts depend on the value’s type, and the align and size attributes on structure members."

Append. "These rule apply to non-opaque types as described below; values of [=buffer=] type do not
have an internal structure, and are not contrained by these rules."

interaction with "valid pointer"

bufferView, bufferArrayView built-ins yield invalid pointer if the original pointer is invalid.
Is that possible?

What does bufferLength return on an invalid pointer? (Is that even possible after type checking?)

6.5.8

"A pointer value is formed in one of the following ways"

• add a case for bufferView

6.5.4

"a bufferView or bufferArrayView built-in function requires a larger size than the buffer’s memory view contains."

The "requires a larger size" is confusing?

This rule belongs in a new set of paragraphs for how to make an invalid pointer rather than invalid reference.

Suggest?:

An invalid pointer is formed by:

• Applying the address-of operator (&) to an invalid memory reference.
• Calling the bufferView or bufferArrayView built-in functions, but the memory view of
  the resulting pointer would otherwise include memory locations outside the memory view of the
  pointer argument.

LGTM. Thanks!

Two typos.

Looks good to me - thank you!