[llvm] [flang-rt] enable IsNamelistNameOrSlash lookahead for scalar namelist items (PR #211224)

[Eugene Epshteyn via llvm-commits]

eugeneepshteyn wrote:

> Do the tests give enough context for the problem I am trying to fix?

I need both a Fortran reproducer and namelist file to get full context (e.g., what kind of I/O that was). It needs to be a github issue, so that we can discuss, in case this goes into the weeds of the Fortran spec, or in case something needs to be tweaked in flang extensions document.

https://github.com/llvm/llvm-project/pull/211224