Treat `TypeInner::ValuePointer` and `TypeInner::Pointer` as equivalent by
converting them to a canonical form before comparison.
Support `ValuePointer` in WGSL type output.
Fixes#1318.
Ensure that each distinct type occurs only once in `Module::types`, so that we
can use `Eq` on `Type` or `TypeInner` for type equivalence, without being
confused by differing `Handle<Type>` values that point to identical types.
This removes a number of duplicate types from the ir snapshots.
Fixes#1385.
* Resurrect texture_storage_* tests
* Test parsing of `var<storage,write>`
* Default storage textures to READ
* Restore default features
* Fix glsl/hlsl/msl/spv front and back ends
* Add missing test outputs
* All-around fixes for the storage access
Co-authored-by: Dzmitry Malyshau <kvarkus@gmail.com>
If validation fails, `Validator` may be left with entries in
`valid_expression_list` and `valid_expression_set`. The validator does clear the
set before examining a function's body, but not the list, which means a
long-lived `Validator` could accumulate an unbounded amount of garbage in the
list.
(Minor cleanup: use structural update syntax where appropriate.)
