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

[Tarun Prabhu via cfe-commits]

tarunprabhu wrote:

```
      if ( (a  .eq. 0) .and.(b. eq. 1)) then
```

It seems like something in [9fb2db1](https://github.com/llvm/llvm-project/commit/9fb2db1e1f42ae10a9d8c1d9410b5f4e719fdac0) has caused a space to appear between `.` and `eq`. Should we be looking at what that commit did more closely or am I missing something obvious? (alas, it wouldn't surprise me if I was)

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