Exercise 5.44: In this section we have focused
on the use of the compile-time environment to produce lexical addresses.  But
there are other uses for compile-time environments.  For instance, in
Exercise 5.38 we increased the efficiency of compiled code by open-coding
primitive procedures.  Our implementation treated the names of open-coded
procedures as reserved words.  If a program were to rebind such a name, the
mechanism described in Exercise 5.38 would still open-code it as a
primitive, ignoring the new binding.  For example, consider the procedure


(lambda (+ * a b x y)
  (+ (* a x) (* b y)))

which computes a linear combination of x and y.  We might call it
with arguments +matrix, *matrix, and four matrices, but the
open-coding compiler would still open-code the + and the * in
(+ (* a x) (* b y)) as primitive + and *.  Modify the
open-coding compiler to consult the compile-time environment in order to
compile the correct code for expressions involving the names of primitive
procedures.  (The code will work correctly as long as the program does not
define or set! these names.)