Bounds declarations

Programmers declare bounds for variables with _Array_ptr, _Nt_array_ptr, or incomplete checked array types as part of the variable declarations. A bounds expression is placed after the declarator and before any initializer, if one is allowed. There are 3 kinds of bounds declarations:

1. count(e): the number of array elements that a pointer points to.
2. bytecount(e): the number of bytes that a pointer points to.
3. bounds(lower, upper): the lower and upper bound for a ponter.
4. bounds(unknown): the pointer has uknown bounds and cannot be used to access memory. Count and bytecount are syntactic sugar for bounds.