(defun test ()
  (let ((data (make-array 3)))
    (symbol-macrolet ((sv data))
      (setf (svref sv 0) 99))
    data))

;;=>
  error:
    The value (SB-SYS:MACRO . DATA) is not of type SB-C::LAMBDA-VAR.
    ==>
      (SB-KERNEL:%SVSET SV 0 99)

[Condition of type TYPE-ERROR]

This means SVREF cannot be used with WITH-SLOTS, for example. My
libraries in quicklisp now fail to compile; I assume others are
affected as well.