[clang-tools-extra] [clang-doc] switched from using relative to absolute paths (PR #93281)

[Paul Kirth via cfe-commits]

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@@ -7,6 +7,7 @@
 // RUN: FileCheck %s -input-file=%t/docs/GlobalNamespace/Rectangle.html -check-prefix=HTML-RECTANGLE
 // RUN: FileCheck %s -input-file=%t/docs/GlobalNamespace/Circle.html -check-prefix=HTML-CIRCLE
 
+// JSON-INDEX: var RootPath = "{{.*}}";
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ilovepi wrote:

Oh, then I'm not 100% sure we want to replace all the `\` w/ `/`. I know you mentioned browser behavior, but I'm not 100% certain that's a great motivation. When I thought it was a URL, there's obviously no issue, but, for a file system path, I'm hesitant to say with confidence that there's no downside.

Also, given the test updates, IDK if this check is particularly useful. I don't see much difference in the check as is, and just 
```
// JSON-INDEX: var RootPath =
```

https://github.com/llvm/llvm-project/pull/93281