Extend "counted_by" attribute to pointer fields of structures. Convert a pointer...

Extend "counted_by" attribute to pointer fields of structures. Convert a pointer reference with counted_by attribute to .ACCESS_WITH_SIZE.

For example:

struct PP {
  size_t count2;
  char other1;
  char *array2 __attribute__ ((counted_by (count2)));
  int other2;
} *pp;

specifies that the "array2" is an array that is pointed by the
pointer field, and its number of elements is given by the field
"count2" in the same structure.

gcc/c-family/ChangeLog:

	* c-attribs.cc (handle_counted_by_attribute): Accept counted_by
	attribute for pointer fields.

gcc/c/ChangeLog:

	* c-decl.cc (verify_counted_by_attribute): Change the 2nd argument
	to a vector of fields with counted_by attribute. Verify all fields
	in this vector.
	(finish_struct): Collect all the fields with counted_by attribute
	to a vector and pass this vector to verify_counted_by_attribute.
	* c-typeck.cc (build_counted_by_ref): Handle pointers with counted_by.
	Add one more argument, issue error when the pointee type is a structure
	or union including a flexible array member.
	(build_access_with_size_for_counted_by): Handle pointers with counted_by.
	(handle_counted_by_for_component_ref): Call build_counted_by_ref
	with the new prototype.

gcc/ChangeLog:

	* doc/extend.texi: Extend counted_by attribute to pointer fields in
	structures. Add one more requirement to pointers with counted_by
	attribute.

gcc/testsuite/ChangeLog:

	* gcc.dg/flex-array-counted-by.c: Update test.
	* gcc.dg/pointer-counted-by-1.c: New test.
	* gcc.dg/pointer-counted-by-2.c: New test.
	* gcc.dg/pointer-counted-by-3.c: New test.
	* gcc.dg/pointer-counted-by.c: New test.