gas: drop .appfile and .appline

These were used originally to represent "# <line> <file>" constructs
inserted by (typically) compilers when pre-processing. Quite some time
ago they were replaced by .linefile though. Since the original
directives were never documented, we ought to be able to remove support
for them. As a result in a number of case function parameter aren't used
anymore and can hence be dropped.

gas/ecoff.c

@@ -2312,7 +2312,7 @@ add_file (const char *file_name, int indx ATTRIBUTE_UNUSED, int fake)
    compiler output, only in hand coded assembler.  */
 
 void
-ecoff_new_file (const char *name, int appfile ATTRIBUTE_UNUSED)
+ecoff_new_file (const char *name)
 {
   if (cur_file_ptr != NULL && filename_cmp (cur_file_ptr->name, name) == 0)
     return;