[libcxx] [llvm] [libcxx] Add `LIBCXX_HAS_TERMINAL_AVAILABLE` CMake option to disable `print` terminal checks (PR #99259)

[Joseph Huber via llvm-commits]

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@@ -199,7 +199,7 @@ _LIBCPP_HIDE_FROM_ABI inline bool __is_terminal([[maybe_unused]] FILE* __stream)
   // the behavior in the test. This is not part of the public API.
 #  ifdef _LIBCPP_TESTING_PRINT_IS_TERMINAL
   return _LIBCPP_TESTING_PRINT_IS_TERMINAL(__stream);
-#  elif _LIBCPP_AVAILABILITY_HAS_PRINT == 0
+#  elif _LIBCPP_AVAILABILITY_HAS_PRINT == 0 || defined(_LIBCPP_HAS_NO_TERMINAL)
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jhuber6 wrote:

This was done with a default x64 Linux build, so it should've had filesystem unless that's off by default.

https://github.com/llvm/llvm-project/pull/99259