ICE from endfile statement

[harperjf]

The endfile statement was in Fortran 66 and is still there in Fortran 2023 but this program shows that executing it causes an internal compiler error for lfortran.

(lf2) john:~/Test/Glist$ cat endfile3.f90
program endfile3 ! endfile was in f66, is in f2023
  implicit none
  integer :: lun = 66
  open(lun,file='scr.txt')
  endfile lun
  print *,'Endfile statement has been executed'
end program endfile3
 
(lf2) john:~/Test/Glist$ lfortran endfile3.f90
Internal Compiler Error: Unhandled exception
Traceback (most recent call last):
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x726858
  Binary file "/lib/x86_64-linux-gnu/libc.so.6", local address: 0x29e3f
  Binary file "/lib/x86_64-linux-gnu/libc.so.6", local address: 0x29d8f
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x600a58
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x7a0a5c
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x78dc13
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x8615d5
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0x82689f
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0xa2e23f
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0xd5b056
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0xd58ea6
  Binary file "/home/john/conda_root/envs/lf2/bin/lfortran", local address: 0xd57de7
LCompilersException: visit_Endfile() not implemented