[clang] [Clang] Allow the value of unroll count to be zero in `#pragma GCC unroll` and `#pragma unroll` (PR #88666)

[Timm Baeder via cfe-commits]

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@@ -423,6 +423,10 @@ Bug Fixes in This Version
 - Fixed a regression in CTAD that a friend declaration that befriends itself may cause
   incorrect constraint substitution. (#GH86769).
 
+- Clang now allowed the value of unroll count to be zero in ``#pragma GCC unroll`` and ``#pragma unroll``.
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tbaederr wrote:

```suggestion
- Clang now allows the value of unroll count to be zero in ``#pragma GCC unroll`` and ``#pragma unroll``.
```

https://github.com/llvm/llvm-project/pull/88666