repair cross-compilation of ftype-scheme-object-pointer (#1038)

Checking whether a parent type represents a Scheme-object ftype
pointer used an accessor technique that does not work for cross
compilation.

Also, repair a documentation typo and a technically too-weak check for
consistent record definition.

Author: mflatt

csug/foreign.stex

@@ -2151,7 +2151,7 @@ The resulting ftype pointer is recognized by
 \scheme{ftype-pointer?} without an \var{ftype-name}.
 
 If \var{ftype-name} is provided, it must be
-\var{ftype-scheme-object-pointer} or a derived Scheme-object pointer
+\scheme{ftype-scheme-object-pointer} or a derived Scheme-object pointer
 type that is defined using \scheme{define-ftype}.
 
 %----------------------------------------------------------------------------

s/ftype.ss

@@ -287,7 +287,7 @@ ftype operators:
   (define ftd-stype (record-accessor rtd/ftd 0))
   (define ftd-size (record-accessor rtd/ftd 1))
   (define ftd-alignment (record-accessor rtd/ftd 2))
-  (define rtd-pm (lambda (x) ($object-ref 'scheme-object x (constant record-type-pm-disp))))
+  (define rtd-pm (csv7:record-field-accessor #!base-rtd 'pm))
   (define-syntax define-ftd-record-type
     (lambda (x)
       (define construct-name

s/record.ss

@@ -640,9 +640,7 @@
                  (unless (eq? ($record-type-descriptor rtd) base-rtd) (squawk "different base rtd"))
                  (unless (eq? (rtd-parent rtd) parent) (squawk "different parent"))
                  (unless (same-fields? (rtd-flds rtd) (if (pair? flds) (cdr flds) (fx- flds 1))) (squawk "different fields"))
-                 (let ([pm (rtd-pm rtd)])
-                   (unless (if alt-pm (eq? pm alt-pm) (or (fixnum? pm) (bignum? pm)))
-                     (squawk "different pointer mask")))
+                 (unless (eqv? (rtd-pm rtd) (or alt-pm pm)) (squawk "different pointer mask"))
                  (unless (= (rtd-mpm rtd) mpm) (squawk "different mutability"))
                  (unless (fx= (rtd-flags rtd) flags) (squawk "different flags"))
                  (unless (eq? (rtd-size rtd) size) (squawk "different size"))