[WGSL] Add PointerDereference AST node

[tadeuzagallo]

5ce16a2

[WGSL] Add PointerDereference AST node
https://bugs.webkit.org/show_bug.cgi?id=251086
<rdar://problem/104599831>

Reviewed by Myles C. Maxfield.

Doesn't include parsing and it's not used yet, but I had to implement it as part
of another patch and figured I might as well commit it as we'll need it later.

* Source/WebGPU/WGSL/AST/AST.h:
* Source/WebGPU/WGSL/AST/ASTForward.h:
* Source/WebGPU/WGSL/AST/ASTNode.h:
* Source/WebGPU/WGSL/AST/ASTPointerDereference.h: Copied from Source/WebGPU/WGSL/AST/AST.h.
* Source/WebGPU/WGSL/AST/ASTStringDumper.cpp:
(WGSL::AST::StringDumper::visit):
* Source/WebGPU/WGSL/AST/ASTStringDumper.h:
* Source/WebGPU/WGSL/AST/ASTVisitor.cpp:
(WGSL::AST::Visitor::visit):
* Source/WebGPU/WGSL/AST/ASTVisitor.h:
* Source/WebGPU/WGSL/Metal/MetalFunctionWriter.cpp:
(WGSL::Metal::FunctionDefinitionWriter::visit):
* Source/WebGPU/WebGPU.xcodeproj/project.pbxproj:

Canonical link: https://commits.webkit.org/259344@main

e03e626

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
✅ 🛠 🧪 merge	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash e03e626)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe
	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
✅ 🛠 🧪 merge	✅ 🛠 watch-sim

[djg]

[webkit-commit-queue]

Committed 259344@main (5ce16a2): https://commits.webkit.org/259344@main

Reviewed commits have been landed. Closing PR #9040 and removing active labels.