fix #37677, unreliable lowering of assignments to gensym'd names (#37717

)

src/ast.scm

@@ -264,9 +264,6 @@
 (define (reset-gensyms)
  (set! *current-gensyms* *gensyms*))
 
-(define (some-gensym? x)
- (or (gensym? x) (memq x *gensyms*)))
-
 (define make-ssavalue
  (let ((ssavalue-counter 0))
  (lambda ()

src/julia-syntax.scm

@@ -1450,7 +1450,9 @@
  (loop (cdr lhss)
  (cons L assigned)
  (cdr rhss)
- (cons (make-assignment temp R) stmts)
+ (if (symbol? temp)
+ (list* (make-assignment temp R) `(local-def ,temp) stmts)
+ (cons (make-assignment temp R) stmts))
  (cons (make-assignment L temp) after)
  (cons temp elts)))))))))
 
@@ -1468,6 +1470,7 @@
  ;; issue #22032
  (let ((temp (gensy)))
  `(block
+ (local-def ,temp)
  (= ,temp (call (core getfield) ,t ,i))
  (= ,(car lhs) ,temp)))
  `(= ,(car lhs)
@@ -1664,6 +1667,7 @@
  ,body))
  `(scope-block ,body))))
  `(block (= ,coll ,(car itrs))
+ (local ,next)
  (= ,next (call (top iterate) ,coll))
  ;; TODO avoid `local declared twice` error from this
  ;;,@(if outer `((local ,lhs)) '())
@@ -2694,8 +2698,7 @@
  (implicit-globals (if toplevel? nonloc-assigned '()))
  (implicit-locals
  (filter (if toplevel?
- ;; make only assigned gensyms implicitly local at top level
- some-gensym?
+ (lambda (v) #f) ;; no implicit locals at top level
  (lambda (v) (and (memq (var-kind v scope #t) '(none static-parameter))
  (not (and soft?
  (or (memq v (scope:implicit-globals scope))