preproc: add dummy %pragma directive

In future versions of NASM we will presumably have "real" pragmas; add
dummy support for the %pragma directive for forward compatibility.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

doc/changes.src

@@ -35,6 +35,10 @@ since 2007.
    included in a shipping product; it is included for completeness
    only.
 
+\b Add the \c{%pragma} preprocessor directive for forward
+   compatibility with future versions of NASM.  At this time no pragmas
+   are implemented and this is merely a dummy directive.
+
 \S{cl-2.12.02} Version 2.12.02
 
 \b Fix preprocessor errors, especially \c{%error} and \c{%warning},

pptok.dat

@@ -1,6 +1,6 @@
 ## --------------------------------------------------------------------------
 ##   
-##   Copyright 1996-2010 The NASM Authors - All Rights Reserved
+##   Copyright 1996-2016 The NASM Authors - All Rights Reserved
 ##   See the file AUTHORS included with the NASM distribution for
 ##   the specific copyright holders.
 ##
@@ -78,6 +78,7 @@
 %macro
 %pathsearch
 %pop
+%pragma
 %push
 %rep
 %repl

preproc.c

@@ -2283,6 +2283,14 @@ static int do_directive(Token * tline)
               tline->text);
         return NO_DIRECTIVE_FOUND;      /* didn't get it */
 
+    case PP_PRAGMA:
+        /*
+         * Currently %pragma doesn't do anything; it is here for
+         * forward compatibility with future versions of NASM.
+         */
+        free_tlist(origline);
+        return DIRECTIVE_FOUND;
+
     case PP_STACKSIZE:
         /* Directive to tell NASM what the default stack size is. The
          * default is for a 16-bit stack, and this can be overriden with