JIT: fix property predicate & selector handling

Commit 89512eda had accientally disabled the JIT's fast
path for structure-type property predicates and selectors.

Re-enable it, but but repair a problem with the way that
impersonator-property operations are handled by the same
code.

pkgs/racket-test-core/tests/racket/chaperone.rktl

@@ -3310,6 +3310,29 @@
                             s-y (lambda (s v) (collect-garbage 'minor) v)
                             s-z (lambda (s v) (collect-garbage 'minor) v))))
 
+
+;; ----------------------------------------
+;; Make sure that a JIT-inlined predicate is sensitive to `prop:impersonator-of`
+
+(let ()
+  (define-values (p:a a? a-ref) (make-impersonator-property 'a))
+
+  (struct posn (x y)
+    #:property prop:impersonator-of
+    (lambda (p) (posn-y p)))
+
+  (define p
+    (impersonate-struct (posn 1 #f) struct:posn
+                        p:a 17))
+
+  (define (f p)
+    (a? p))
+  (set! f f)
+
+  (test #t f p)
+  (test #t f (posn 0 p))
+  (test #f f (posn 0 #f)))
+
 ;; ----------------------------------------
 
 (report-errs)

pkgs/racket-test-core/tests/racket/struct.rktl

@@ -1216,6 +1216,25 @@
   (-set! v 3 'ok)
   (test 'ok -ref v 3))
 
+;; ----------------------------------------
+;; Make sure that a JIT-inlined predicate doesn't
+;; fail improperly on chaperones and struct types
+
+(let ()
+  (define-values (prop:a a? a-ref) (make-struct-type-property 'a))
+
+  (struct posn (x y)
+    #:property prop:a 'yes)
+
+  (define (f p)
+    (and (a? p)
+         (a-ref p 'no)))
+  (set! f f)
+  
+  (test 'yes f (posn 1 2))
+  (test 'yes f struct:posn)
+  (test #f f 5))
+
 ;; ----------------------------------------
 
 (report-errs)

racket/src/racket/src/jitcommon.c

@@ -2164,8 +2164,6 @@ static int common4b(mz_jit_state *jitter, void *_data)
       (void)jit_bnei_i(refslow, JIT_R2, prim_other_type);
       CHECK_LIMIT();
 
-      (void)jit_jmpi(refslow);
-
       /* Check argument: */
       (void)jit_bmsi_ul(refno, JIT_R1, 0x1);
       jit_ldxi_s(JIT_R2, JIT_R1, &((Scheme_Object *)0x0)->type);
@@ -2208,9 +2206,16 @@ static int common4b(mz_jit_state *jitter, void *_data)
 
       /* target struct-type property in V1 */
       jit_ldxi_p(JIT_V1, JIT_R0, &((Scheme_Primitive_Closure *)0x0)->val);
-    
+
       ref3 = jit_beqr_p(jit_forward(), JIT_R2, JIT_V1);
-    
+
+      /* If we're looking for an impersonator property, then we're
+         looking in the wrong place. But it's not ok to fail, because
+         we may need to go through a `prop:impersonator-of` mapping to
+         succeed. So, bail out for an impersonator-property operation,
+         since there was at least one property here. */
+      (void)mz_beqi_t(refslow, JIT_V1, scheme_chaperone_property_type, JIT_R2);
+
       mz_get_local_p(JIT_V1, JIT_LOCAL3);
       (void)jit_jmpi(refloop);