[flang] Extension: getcwd intrinsic for OpenRadioss application

[DavidTruby]

The getcwd intrinsic is an extension provided by some other Fortran compilers (for example gfortran). This extension is used by OpenRadioss.

Arguments:

C	The type shall be CHARACTER and of default kind.
STATUS	(Optional) status flag. Returns 0 on success, a system specific and nonzero error code otherwise.

Example:

PROGRAM test_getcwd
  CHARACTER(len=255) :: cwd
  CALL getcwd(cwd)
  WRITE(*,*) TRIM(cwd)
END PROGRAM

[DavidTruby]

This extension seems to be supported by semantics but results in a linker error if used