[libunwind] libunwind: Remove OS requirements from tests to make them run on more OSes (PR #167642)

[Alexander Richardson via cfe-commits]

================
@@ -8,7 +8,9 @@
 //===----------------------------------------------------------------------===//
 
 // Ensure that leaf function can be unwund.
-// REQUIRES: target={{(aarch64|loongarch64|riscv64|s390x|x86_64)-.+linux.*}}
+// REQUIRES: target={{(aarch64|loongarch64|riscv64|s390x|x86_64)-.+}}
+// UNSUPPORTED: system-windows
+// UNSUPPORTED: target={{.*-windows-gnu}}
----------------
arichardson wrote:

```suggestion
// UNSUPPORTED: target={{.*-windows.*}}
```

https://github.com/llvm/llvm-project/pull/167642