Update WHLSL to Metal tester with semantics

Update WHLSL to Metal tester with semantics
https://bugs.webkit.org/show_bug.cgi?id=190416
<rdar://problem/45145139>

Reviewed by Myles Maxfield.

A few small changes to the WHLSL to Metal tools:
- Make it compile by adding some missing JS files :)
- Add semantics to the default shader
- Add FIXMEs to the other shaders
- Create an in-browser test for the WHLSLToMetal codepath
- Fix typos in the semantics checker

* WebGPUShadingLanguageRI/Checker.js:
(Checker.prototype._checkSemantics.checkSemanticTypes):
(Checker.prototype._checkSemantics.checkSemanticForShaderType):
* WebGPUShadingLanguageRI/Metal/WHLSL Tests/Core/Compiler.m:
* WebGPUShadingLanguageRI/Metal/WHLSL Tests/Core/Demo shaders/Default.whlsl:
* WebGPUShadingLanguageRI/Metal/WHLSL Tests/Core/Demo shaders/Julia.whlsl:
* WebGPUShadingLanguageRI/Metal/WHLSL Tests/Core/Demo shaders/Mandelbrot.whlsl:
* WebGPUShadingLanguageRI/Metal/WHLSL Tests/WHLSL Tests.xcodeproj/project.pbxproj:
* WebGPUShadingLanguageRI/Metal/WhlslToMsl.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@236992 268f45cc-cd09-0410-ab3c-d52691b4dbfc