[clang] Disable Driver/env.c on AIX (NFC) (PR #161874)

[Aiden Grossman via cfe-commits]

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@@ -1,5 +1,7 @@
 // Some assertions in this test use Linux style (/) file paths.
-// UNSUPPORTED: system-windows
+// UNSUPPORTED: system-windows, system-aix
+// FIXME: Use LIBPATH on AIX
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boomanaiden154 wrote:

Nit: It would be better if the FIXME line was above the unsupported line. Then we have an explanation for windows being unsupported on one line, the explanation for AIX being unsupported on the next, matching the ordering in the line specifying unsupported platforms.

https://github.com/llvm/llvm-project/pull/161874