Generate private constructor for object

#KT-9510 Fixed

compiler/testData/codegen/box/privateConstructors/captured.kt

@@ -0,0 +1,10 @@
+public open class Outer private constructor(val s: String) {
+
+    companion object {
+        fun test () =  { Outer("OK") }()
+    }
+}
+
+fun box(): String {
+    return Outer.test().s
+}

compiler/testData/codegen/bytecodeText/staticFields/classObject.kt

@@ -4,4 +4,4 @@ class A {
     }
 }
 // A and companion object constructor call
-// 4 ALOAD 0
+// 3 ALOAD 0

compiler/testData/codegen/bytecodeText/staticFields/classObjectSyntheticAccessor.kt

@@ -4,5 +4,5 @@ class A {
     }
 }
 // A and companion object constructor call
-// 4 ALOAD 0
+// 3 ALOAD 0
 // 1 synthetic access\$getR