[clang] [flang] [flang] Preserve fixed form in fc1 -x value (PR #117563)

[David Truby via cfe-commits]

DavidTruby wrote:

I'm not sure if it's explicitly documented anywhere but there's a lot of tests, as you can see in the patch that introduced the behaviour here: https://reviews.llvm.org/D106727

Essentially since that patch the output is _always_ valid 72 width fixed form, and if the input was free form it'll _also_ be valid free form (but still valid fixed form too! It's possible to write in a style that can be compiled as both)

https://github.com/llvm/llvm-project/pull/117563