[clang] [clang-repl][AIX][zOS] Disable clang/test/Interpreter tests on AIX and zOS (NFC) (PR #153587)

[Kelvin Li via cfe-commits]

================
@@ -1,2 +1,5 @@
-if "host-supports-jit" not in config.available_features:
+import sys
+
+# clang-repl is not supported on AIX and zOS
+if "host-supports-jit" not in config.available_features or sys.platform == "aix" or sys.platform == "zos":
----------------
kkwli wrote:

> I think it amounts to the same thing, but since we have lit features for these things already, we should use them. For instance file elsewhere does:
> 
> ```
> if "system-aix" in config.available_features:
>     config.unsupported = True
> ```
> 
> Though that is in `llvm` and the feature is added by llvm/utils/lit/lit/llvm/config.py. You might have to add the zOS feature to clang's equivalent file.

Thanks @DavidSpickett. I update the patch with your suggestions.

https://github.com/llvm/llvm-project/pull/153587