* [glsl-in] Add initial pre-processor

* [glsl-in] Tweak preprocessor after review

- Add IfState struct
- Use FastHashMap to pre-defines
- Use ok-or() for some errors

* [glsl-in] Remove Option in defines arg

* [clippy] disable match_like_matches_macro for now

* [wgsl-in] Return error instead of panic

* [typifier] Convert panics to return error

Still one panic in clone impl for Resolution,
disabled clippy for that one

* [spv-in] REturn error instead of panic'ing

* [spv-out] Return error instead of panic'ing

* [typifier] Use IncompatibleOperand(s) error

Instead of just Other

* [typifier] Use Expression for op in Error

For IncompatibleOperands

* [typifier] revert last commit

Have single place where advancing to next line

* [glsl-in] make consume_token a lexer method

* [glsl-in] fix lex for 1.41

* [glsl-in] Implement swizzle for r-values

Related to #210

* [glsl-in] Just return Result from field_selection

Removed unneccessary Otion in return type

* [glsl-in] Always match on type in field_selection

* [glsl.in] Borrow by value in field_selection

There's no legend explaining what symbols mean for supported end-points, but it seems to be following the same format at wgpu. This PR copies wgpu's legend.

* [glsl-in] Support anonymous global uniforms

Partly fixes #210

* [glsl-in] Handle anon global structs in fn prelude

* [glsl-in] consolidate tests

- remove simple lex test as was covered by others
- combine related tests to single function
- remove redundant prefix in test names

* [glsl-in] Consolidtae lex tests further

Complete expression/statement support in MSL, refactor conversion methods in WGSL, and remove Statement::Empty

* Added support for glsl core version up to 400

* Added 330 to the list supported versions

* Added links to all extensions and fixed a extension being wrongfully activated

* Cleanup and check for image formats

* Removed useless extension and location on layout

* Added support for external functions and fixed global names

* Typefier allow Scalars in distance and length

* Addressed comments

* Fixed extension appearing after body

* Fixed entry point not being generated