New test.

From-SVN: r21371

gcc/testsuite/g77.f-torture/execute/io0.f

+*     Preliminary tests for a few things in the i/o library.
+*     Thrown together by Dave Love not from specific bug reports --
+*     other ideas welcome.
+
+      character *(*) fmt
+      parameter (fmt='(1x,i3,f5.1)')
+*     Scratch file makes sure we can use one and avoids dealing with
+*     explicit i/o in the testsuite.
+      open(90, status='scratch') ! try a biggish unit number
+      write(90, '()')           ! extra record for interest
+*     Formatted i/o can go wild (endless loop AFAIR) if we're wrongly
+*     assuming an ANSI sprintf.
+      write(90, fmt) 123, 123.0
+      backspace 90              ! backspace problems reported on DOSish systems
+      read(90, fmt) i, r
+      endfile 90
+      if (i/=123 .or. nint(r)/=123) call abort
+      rewind 90                 ! make sure we can rewind too
+      read(90, '()')
+      read(90, fmt) i, r
+      if (i/=123 .or. nint(r)/=123) call abort
+      close(90)
+*     Make sure we can do unformatted i/o OK.  This might be
+*     problematic on DOS-like systems if we've done an fopen in text
+*     mode, not binary.     
+      open(90, status='scratch', access='direct', form='unformatted',
+     +     recl=8)
+      write(90, rec=1) 123, 123.0
+      read(90, rec=1) i, r
+      if (i/=123 .or. nint(r)/=123) call abort
+      close(90)
+      open(90, status='scratch', form='unformatted')
+      write(90) 123, 123.0
+      backspace 90
+      read(90) i, r
+      if (i/=123 .or. nint(r)/=123) call abort
+      close(90)
+      end