Merge branch 'branch-2.6' into maint

* origin/branch-2.6:
  regen
  yacc.c: do not define location support when not using locations
  maint: be compilable with GCC 4.0
  tests: address a warning from GCC 4.4
  tests: don't use options that Clang does not support
  tests: restore the tests on -Werror
  regen
  parse-gram: update the Bison interface
  fix comment

data/c.m4

@@ -602,7 +602,7 @@ m4_define([b4_YYDEBUG_define],
 #  endif
 # else /* ! defined YYDEBUG */
 #  define ]b4_api_PREFIX[DEBUG ]b4_debug_flag[
-# endif /* ! defined ]b4_api_PREFIX[DEBUG */
+# endif /* ! defined YYDEBUG */
 #endif  /* ! defined ]b4_api_PREFIX[DEBUG */]])[]dnl
 ])
 

data/yacc.c

@@ -769,10 +769,9 @@ while (YYID (0))
 #define YYTERROR	1
 #define YYERRCODE	256
 
+]b4_locations_if([[
 ]b4_yylloc_default_define[
 #define YYRHSLOC(Rhs, K) ((Rhs)[K])
-]b4_locations_if([[
-
 
 /* YY_LOCATION_PRINT -- Print the location on the stream.
    This macro was not mandated originally: define only if we know
@@ -787,18 +786,14 @@ while (YYID (0))
 # else
 #  define YY_LOCATION_PRINT(File, Loc) ((void) 0)
 # endif
-#endif]], [[
-
-
-/* This macro is provided for backward compatibility. */
-
+#endif]],
+[[/* This macro is provided for backward compatibility. */
 #ifndef YY_LOCATION_PRINT
 # define YY_LOCATION_PRINT(File, Loc) ((void) 0)
 #endif]])[
 
 
 /* YYLEX -- calling `yylex' with the right arguments.  */
-
 #ifdef YYLEX_PARAM
 # define YYLEX yylex (]b4_pure_if([&yylval[]b4_locations_if([, &yylloc]), ])[YYLEX_PARAM)
 #else