[llvm] [flang-rt] Fixes EXECUTE_COMMAND_LINE() status management and double buffering (PR #184285)

[Eugene Epshteyn via llvm-commits]

eugeneepshteyn wrote:

See https://github.com/llvm/llvm-project/issues/92929 , which is the original issue that caused flang behavior to change.

https://github.com/llvm/llvm-project/pull/184285