gcc/: Merge definitions of array_type_nelts_top

There were two identical definitions, and none of them are available
where they are needed for implementing a number-of-elements-of
operator.  Merge them, and provide the single definition in
gcc/tree.{h,cc}, where it's available for that operator, which will be
added in a following commit.

gcc/ChangeLog:

	* tree.h (array_type_nelts_top)
	* tree.cc (array_type_nelts_top):
	Define function (moved from gcc/cp/).

gcc/cp/ChangeLog:

	* cp-tree.h (array_type_nelts_top)
	* tree.cc (array_type_nelts_top):
	Remove function (move to gcc/).

gcc/rust/ChangeLog:

	* backend/rust-tree.h (array_type_nelts_top)
	* backend/rust-tree.cc (array_type_nelts_top):
	Remove function.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

gcc/cp/cp-tree.h

@@ -8121,7 +8121,6 @@ extern tree build_exception_variant		(tree, tree);
 extern void fixup_deferred_exception_variants   (tree, tree);
 extern tree bind_template_template_parm		(tree, tree);
 extern tree array_type_nelts_total		(tree);
-extern tree array_type_nelts_top		(tree);
 extern bool array_of_unknown_bound_p		(const_tree);
 extern tree break_out_target_exprs		(tree, bool = false);
 extern tree build_ctor_subob_ref		(tree, tree, tree);

gcc/cp/tree.cc

@@ -3076,19 +3076,6 @@ cxx_print_statistics (void)
 	     depth_reached);
 }
 
-/* Return, as an INTEGER_CST node, the number of elements for TYPE
-   (which is an ARRAY_TYPE).  This counts only elements of the top
-   array.  */
-
-tree
-array_type_nelts_top (tree type)
-{
-  return fold_build2_loc (input_location,
-		      PLUS_EXPR, sizetype,
-		      array_type_nelts_minus_one (type),
-		      size_one_node);
-}
-
 /* Return, as an INTEGER_CST node, the number of elements for TYPE
    (which is an ARRAY_TYPE).  This one is a recursive count of all
    ARRAY_TYPEs that are clumped together.  */

gcc/rust/backend/rust-tree.cc

@@ -859,19 +859,6 @@ is_empty_class (tree type)
   return CLASSTYPE_EMPTY_P (type);
 }
 
-// forked from gcc/cp/tree.cc array_type_nelts_top
-
-/* Return, as an INTEGER_CST node, the number of elements for TYPE
-   (which is an ARRAY_TYPE).  This counts only elements of the top
-   array.  */
-
-tree
-array_type_nelts_top (tree type)
-{
-  return fold_build2_loc (input_location, PLUS_EXPR, sizetype,
-			  array_type_nelts_minus_one (type), size_one_node);
-}
-
 // forked from gcc/cp/tree.cc builtin_valid_in_constant_expr_p
 
 /* Test whether DECL is a builtin that may appear in a

gcc/rust/backend/rust-tree.h

@@ -2993,8 +2993,6 @@ extern location_t rs_expr_location (const_tree);
 extern int
 is_empty_class (tree type);
 
-extern tree array_type_nelts_top (tree);
-
 extern bool
 is_really_empty_class (tree, bool);
 

gcc/tree.cc

@@ -3732,6 +3732,19 @@ array_type_nelts_minus_one (const_tree type)
 	  ? max
 	  : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
 }
+
+/* Return, as an INTEGER_CST node, the number of elements for TYPE
+   (which is an ARRAY_TYPE).  This counts only elements of the top
+   array.  */
+
+tree
+array_type_nelts_top (tree type)
+{
+  return fold_build2_loc (input_location,
+		      PLUS_EXPR, sizetype,
+		      array_type_nelts_minus_one (type),
+		      size_one_node);
+}
 
 /* If arg is static -- a reference to an object in static storage -- then
    return the object.  This is not the same as the C meaning of `static'.

gcc/tree.h

@@ -4930,6 +4930,7 @@ extern tree build_method_type (tree, tree);
 extern tree build_offset_type (tree, tree);
 extern tree build_complex_type (tree, bool named = false);
 extern tree array_type_nelts_minus_one (const_tree);
+extern tree array_type_nelts_top (tree);
 
 extern tree value_member (tree, tree);
 extern tree purpose_member (const_tree, tree);