[libc-commits] [libc] [libc] Add getc, ungetc, fflush to enable libc++ iostream on baremetal (PR #175530)

[Paul Kirth via libc-commits]

ilovepi wrote:

We're seeing failures on Windows in stage2 builds with this patch.

Bot: https://ci.chromium.org/ui/p/fuchsia/builders/prod/clang-windows-x64/b8690067288462479969/blamelist

Logs: https://logs.chromium.org/logs/fuchsia/buildbucket/cr-buildbucket/8690067288462479969/+/u/clang/build/stdout

```
[73/2673](65) Generating header stdckdint.h from C:/b/s/w/ir/x/w/llvm-llvm-project/runtimes/../libc/include/stdckdint.yaml
FAILED: C:/b/s/w/ir/x/w/llvm_build/tools/clang/stage2-bins/include/armv7em-unknown-none-eabi/stdckdint.h 
libc\include\CMakeFiles\stdckdint.h-4ef000b.bat aa87def7fde3a956
goto was unexpected at this time.
```

Could you take a look, and revert if the fix to header gen isn't obvious/fast?

https://github.com/llvm/llvm-project/pull/175530