[clang] [Driver] Find vendor-prefixed musl GCC toolchains (PR #206477)

[Adeel Mujahid via cfe-commits]

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@@ -541,6 +546,7 @@ Attribute Changes in Clang
   diagnosed and ignored when applied to anything else. Additionally, calling
   a function marked ``noreturn`` from a function marked ``const`` or ``pure``
   is now diagnosed as undefined behavior (#GH129022).
+  diagnosed and ignored when applied to anything else.
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am11 wrote:

```suggestion
```

https://github.com/llvm/llvm-project/pull/206477