[flang-commits] [flang] [Flang] remove assert using femode_t from AIX (PR #74500)

[Peter Klausler via flang-commits]

klausler wrote:

`femode_t` is a fairly new addition to the C standard; you could test `__STDC_VERSION__`.  Or just delete the assertion for now.

https://github.com/llvm/llvm-project/pull/74500