Minor: add tests for KT-45893

compiler/testData/codegen/box/ranges/forInFloatRangeWithCustomIterator.kt

@@ -0,0 +1,29 @@
+// IGNORE_BACKEND: JVM
+// WITH_RUNTIME
+// KJS_WITH_FULL_RUNTIME
+
+operator fun ClosedRange<Float>.iterator() =
+    object : Iterator<Float> {
+        private var current = this@iterator.start
+        private val end = this@iterator.endInclusive
+
+        override fun hasNext(): Boolean =
+            current <= end
+
+        override fun next(): Float {
+            val next = current
+            current += 0.125f
+            return next
+        }
+    }
+
+fun box(): String {
+    var s = 0.0
+    for (x in 0.0f .. 1.0f) {
+        s += x
+    }
+    if (s != 4.5)
+        return "Failed: $s"
+
+    return "OK"
+}