onnxruntime

50e6235a - [js/web] allow ShaderHelper to use internal (non-I/O) variables (#18525)

[js/web] allow ShaderHelper to use internal (non-I/O) variables (#18525) ### Description This PR includes a change that inspired from #18452 to resolve a requirement: a shader may depend on an instance of `IndicesHelper` to generate WGSL code snippet, but the IndicesHelper instance is not necessarily an input/output of the program. So the existing `declareVariables()` function does not work with this scenario. In order to support this requirement, I added this "use" function to `interface ShaderHelper`, which takes a helper-like object as parameter. The hidden implementation `ShaderHelperImpl` class will iterate the helpers and call `impl()` for each. @axinging @qjia7