[flang-commits] [flang] fix optional wait wrongly treated as false (PR #78149)

[Yi Wu via flang-commits]

yi-wu-arm wrote:

When testing with
```fortran
program bug
  call inner("sleep 2 && echo hi")
  print *, "Direct printout line"
contains
  subroutine inner(cmd, wait, exitstatarg, cmdstatarg, cmdmsgarg)
    character(20) :: cmd
    logical, optional :: wait
    integer, optional :: exitstatarg, cmdstatarg
    character(128), optional :: cmdmsgarg
    integer :: localvar
    call execute_command_line(cmd, wait, exitstatarg, localvar, cmdmsgarg)
  end subroutine
end
```
The console print out would be:
```
```
And when set wait to false,
```
```

https://github.com/llvm/llvm-project/pull/78149