Setf: SETF expander for MEM-AREF.
Function: Like MEM-REF except for accessing 1d arrays.
Compiler-Macro: Compiler macro to open-code MEM-AREF when TYPE (and eventually INDEX).
(row-major-aref array index)
Function: Return the element of array corressponding to the row-major index. This is SETF'able.