Fixes#1745: Support out-of-order module scope declarations in WGSL
Fixes#1044: Forbid local variable shadowing in WGSL
Fixes#2076: [wgsl-in] no error for duplicated type definition
Fixes#2071: Global item does not support 'const'
Fixes#2105: [wgsl-in] Type aliases for a vecN<T> doesn't work when constructing vec from a single argument
Fixes#1775: Referencing a function without a return type yields an unknown identifier error.
Fixes#2089: Error span reported on the declaration of a variable instead of its use
Fixes#1996: [wgsl-in] Confusing error: "expected unsigned/signed integer literal, found '1'"
Separate parsing from lowering by generating an AST, which desugars as
much as possible down to something like Naga IR. The AST is then used
to resolve identifiers while lowering to Naga IR.
Co-authored-by: Teodor Tanasoaia <28601907+teoxoy@users.noreply.github.com>
Co-authored-by: Jim Blandy <jimb@red-bean.com>
Minimize allocation in the namer. Heap-allocate string only when needed to
provide an owned key for a hash table, or to hold synthesized text. Try to reuse
allocations.
Many unnecessary trailing `_` characters are removed from test output. These
were all superfluous; separators are still inserted where necessary.
