Constify few functions in tree.c

[Jan Hubicka]

Hi,
this patch turns some paramters to const_tree.  Bootstrapped/regtested 
ppc64-linux,
comitted as obvious.

Honza

        * tree.c (prototype_p, virtual_method_call_p, obj_type_ref_class,
        is_typedef_decl, typedef_variant_p): Constify.
        * tree.h (prototype_p, virtual_method_call_p, obj_type_ref_class,
        is_typedef_decl, typedef_variant_p): Constify.
Index: tree.c
===================================================================
--- tree.c      (revision 223625)
+++ tree.c      (working copy)
@@ -11579,7 +11579,7 @@
 /* Return true if TYPE has a prototype.  */
 
 bool
-prototype_p (tree fntype)
+prototype_p (const_tree fntype)
 {
   tree t;
 
@@ -12005,7 +12005,7 @@
    can't apply.) */
 
 bool
-virtual_method_call_p (tree target)
+virtual_method_call_p (const_tree target)
 {
   if (TREE_CODE (target) != OBJ_TYPE_REF)
     return false;
@@ -12026,7 +12026,7 @@
 /* REF is OBJ_TYPE_REF, return the class the ref corresponds to.  */
 
 tree
-obj_type_ref_class (tree ref)
+obj_type_ref_class (const_tree ref)
 {
   gcc_checking_assert (TREE_CODE (ref) == OBJ_TYPE_REF);
   ref = TREE_TYPE (ref);
@@ -12124,7 +12124,7 @@
 /* Returns true if X is a typedef decl.  */
 
 bool
-is_typedef_decl (tree x)
+is_typedef_decl (const_tree x)
 {
   return (x && TREE_CODE (x) == TYPE_DECL
           && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
@@ -12133,7 +12133,7 @@
 /* Returns true iff TYPE is a type variant created for a typedef. */
 
 bool
-typedef_variant_p (tree type)
+typedef_variant_p (const_tree type)
 {
   return is_typedef_decl (TYPE_NAME (type));
 }
Index: tree.h
===================================================================
--- tree.h      (revision 223625)
+++ tree.h      (working copy)
@@ -4375,9 +4375,9 @@
 extern tree create_artificial_label (location_t);
 extern const char *get_name (tree);
 extern bool stdarg_p (const_tree);
-extern bool prototype_p (tree);
-extern bool is_typedef_decl (tree x);
-extern bool typedef_variant_p (tree);
+extern bool prototype_p (const_tree);
+extern bool is_typedef_decl (const_tree x);
+extern bool typedef_variant_p (const_tree);
 extern bool auto_var_in_fn_p (const_tree, const_tree);
 extern tree build_low_bits_mask (tree, unsigned);
 extern bool tree_nop_conversion_p (const_tree, const_tree);
@@ -4544,8 +4544,8 @@
 extern location_t tree_nonartificial_location (tree);
 extern tree block_ultimate_origin (const_tree);
 extern tree get_binfo_at_offset (tree, HOST_WIDE_INT, tree);
-extern bool virtual_method_call_p (tree);
-extern tree obj_type_ref_class (tree ref);
+extern bool virtual_method_call_p (const_tree);
+extern tree obj_type_ref_class (const_tree ref);
 extern bool types_same_for_odr (const_tree type1, const_tree type2,
                                bool strict=false);
 extern bool contains_bitfld_component_ref_p (const_tree);