gas: abort in new_logical_line_flags

[Alan Modra]

.linefile 0.

hits the "case 1 << 3" abort in new_logical_line_flags with line_number
of -1.

Similar to commit b60f6a628897, this fixes the abort by extending the
meaning of .linefile in user code to restore the physical line for
".linefile 0 .".

	* input-scrub.c (new_logical_line_flags <case 1<<3>): Don't
	abort on negative line number, instead restore physical line
	for ".linefile 0".

diff --git a/gas/input-scrub.c b/gas/input-scrub.c
index afb80ef2ce0..2b90632040b 100644
--- a/gas/input-scrub.c
+++ b/gas/input-scrub.c
@@ -495,7 +495,12 @@ new_logical_line_flags (const char *fname, /* DON'T destroy it!  We point to it!
       /* FIXME: we could check that include nesting is correct.  */
       break;
     case 1 << 3:
-      if (line_number < 0 || fname != NULL)
+      /* s_linefile conditionally decrements the line depending on
+	 whether '\n' is seen.  */
+      if (line_number < 0
+	  || (line_number == 0 && input_line_pointer[-1] != '\n'))
+	line_number = physical_input_line;
+      if (fname != NULL)
 	abort ();
       if (next_saved_file == NULL)
 	fname = physical_input_file;

-- 
Alan Modra