Port to GCC 2.95. First two problems reported by Michael Deutschmann in

<http://lists.gnu.org/archive/html/bug-bison/2006-09/msg00018.html>.

* src/parse-gram.y (symbol_declaration): Don't put statements
before declarations; it's not portable to C89.
* src/scan-code.l (handle_action_at): Likewise.

* src/scan-code.l: Always initialize braces_level; the old code
left it uninitialized and therefore had undefined behavior.

Don't attempt to redefine 'assert', since it runs afoul of
systems where standard headers (mistakenly) include <assert.h>.
Instead, define and use our own alternative, called 'aver'.
* src/reader.c: Don't include assert.h, since we no longer
use assert.
* src/scan-code.l: Likewise.
* src/system.h (assert): Remove, replacing with....
(aver): New function, taking a bool arg.  All uses changed.
* src/tables.c (pack_vector): Ensure that aver arg is bool,
not merely an integer.

src/LR0.c

@@ -1,7 +1,7 @@
 /* Generate the nondeterministic finite state machine for Bison.
 
-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2004, 2005 Free
-   Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2004, 2005, 2006
+   Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -282,7 +282,7 @@ save_reductions (state *s)
 	  if (r == 0)
 	    {
 	      /* This is "reduce 0", i.e., accept. */
-	      assert (!final_state);
+	      aver (!final_state);
 	      final_state = s;
 	    }
 	}