js-on-sx: fix js-string-repeat arity collision, repeat() raises RangeError on neg/inf

lib/js/runtime.sx

@@ -3238,12 +3238,18 @@
 
 (define
   js-string-repeat
+  (fn
+    (s n)
+    (js-string-repeat-loop s n "")))
+
+(define
+  js-string-repeat-loop
   (fn
     (s n acc)
     (if
       (<= n 0)
       acc
-      (js-string-repeat s (- n 1) (str acc s)))))
+      (js-string-repeat-loop s (- n 1) (str acc s)))))
 
 (define
   js-string-pad
@@ -3383,7 +3389,16 @@
       ((= name "trimStart") (fn () (js-trim-left s)))
       ((= name "trimEnd") (fn () (js-trim-right s)))
       ((= name "repeat")
-        (fn (n) (js-string-repeat s (js-num-to-int n) "")))
+        (fn
+          (n)
+          (let
+            ((nn (js-to-number n)))
+            (cond
+              ((or (< nn 0) (= nn (js-infinity-value)))
+                (raise
+                  (js-new-call RangeError
+                    (js-args "Invalid count value"))))
+              (else (js-string-repeat-loop s (js-num-to-int nn) ""))))))
       ((= name "padStart")
         (fn
           (&rest args)
@@ -5732,12 +5747,6 @@
         (if (> (len sp) 10) (js-string-slice sp 0 10) sp))
       (else ""))))
 
-(define
-  js-string-repeat
-  (fn
-    (s n)
-    (if (<= n 0) "" (str s (js-string-repeat s (- n 1))))))
-
 (define
   js-json-unwrap-primitive
   (fn