Add index entries for @defconstructor (and friends). Also add

code that skips over them when building the search indices.
Overall, this means that the only change most people would see
is that multiple constructors in the same class will get a warning
(and there was one of those, so fixed that too).

Also, Rackety. Specifically, transformed this surprising combination
of constructs (where all caps are placeholders for something specific):

((if PRED
     (λ (c mk) BODY2)
     (λ (c mk) BODY1))
 content
 (lambda (tag) BODY3))

into this one:

(define (mk tag) BODY3)
(if PRED
    BODY1{c:=content}
    BODY2{c:=content})

original commit: 8ee76c9547899f62e6f28eba1cdbba1f4d54c399

collects/scribble/manual-struct.rkt

@@ -9,6 +9,7 @@
                        [from-libs (listof module-path?)])]
  [(method-index-desc exported-index-desc) ([method-name symbol?]
                                            [class-tag tag?])]
+ [(constructor-index-desc exported-index-desc) ([class-tag tag?])]
  [(procedure-index-desc exported-index-desc) ()]
  [(thing-index-desc exported-index-desc) ()]
  [(struct-index-desc exported-index-desc) ()]

collects/scribble/private/manual-method.rkt

@@ -11,6 +11,7 @@
 ; XXX unknown contracts
 (provide *method **method
          method-tag
+         constructor-tag
          name-this-object)
 
 (define-syntax-rule (method a b)
@@ -23,25 +24,26 @@
   (**method sym id))
 
 (define (**method sym id/tag)
-  (let ([content (list (symbol->string sym))])
-    ((if (identifier? id/tag)
-       (lambda (c mk)
-         (make-delayed-element
-          (lambda (ren p ri)
-            (let ([tag (find-scheme-tag p ri id/tag #f)])
-              (if tag (list (mk tag)) content)))
-          (lambda () (car content))
-          (lambda () (car content))))
-       (lambda (c mk) (mk id/tag)))
-     content
-     (lambda (tag)
-       (make-element symbol-color
-                     (list (make-link-element value-link-color content
-                                              (method-tag tag sym))))))))
+  (define content (list (symbol->string sym)))
+  (define (mk tag)
+    (make-element symbol-color
+                  (list (make-link-element value-link-color content
+                                           (method-tag tag sym)))))
+  (if (identifier? id/tag)
+      (make-delayed-element
+       (λ (ren p ri)
+         (let ([tag (find-scheme-tag p ri id/tag #f)])
+           (if tag (list (mk tag)) content)))
+       (λ () (car content))
+       (λ () (car content)))
+      (mk id/tag)))
 
 (define (method-tag vtag sym)
   (list 'meth (list (cadr vtag) sym)))
 
+(define (constructor-tag vtag)
+  (list 'construtor (cadr vtag)))
+
 (define (name-this-object type-sym)
   (to-element
    (string->symbol

collects/scribble/private/manual-proc.rkt

@@ -283,11 +283,40 @@
                (syntax->datum stx-id) names)))
     (define tagged
       (cond
-        [(eq? mode 'new)
-         (make-element #f (list (racket new) spacer (to-element within-id)))]
-        [(eq? mode 'make)
-         (make-element
-          #f (list (racket make-object) spacer (to-element within-id)))]
+        [(or (eq? mode 'new)
+             (eq? mode 'make))
+         (define content
+           (list (if (eq? mode 'new)
+                     (racket new)
+                     (racket make-object))))
+         (define new-elem
+           (if first?
+               (let* ([target-maker (id-to-target-maker within-id #f)])
+                 (if target-maker
+                     (target-maker
+                      content
+                      (lambda (ctag)
+                        (let ([tag (constructor-tag ctag)])
+                          (make-toc-target-element
+                           #f
+                           (list (make-index-element
+                                  #f
+                                  content
+                                  tag
+                                  (list (datum-intern-literal (symbol->string (syntax-e within-id))) 
+                                        (if (eq? mode 'new)
+                                            "new"
+                                            "make-object"))
+                                  content
+                                  (with-exporting-libraries
+                                   (lambda (libs)
+                                     (make-constructor-index-desc
+                                      (syntax-e within-id)
+                                      libs ctag)))))
+                           tag))))
+                     (car content)))
+               (car content)))
+         (make-element #f (list new-elem spacer (to-element within-id)))]
         [(eq? mode 'send)
          (make-element
           #f

collects/scribblings/scribble/manual.scrbl

@@ -1586,3 +1586,12 @@ from @racket[exported-index-desc] names the class or interface that
 contains the method. The @racket[method-name] field names the method.
 The @racket[class-tag] field provides a pointer to the start of the
 documentation for the method's class or interface.}
+
+@defstruct[(constructor-index-desc exported-index-desc) ([class-tag tag?])]{
+
+Indicates that the index entry corresponds to a constructor
+via @racket[defconstructor] and company. The @racket[_name] field
+from @racket[exported-index-desc] names the class or interface that
+contains the method. 
+The @racket[class-tag] field provides a pointer to the start of the
+documentation for the method's class or interface.}