KT-5248 Don't wrap variable if it is captured only in inlined closures

Remove non-escaping Ref's on bytecode postprocessing pass.

compiler/testData/codegen/box/closures/capturedVarsOptimization/capturedInInlineOnlyCAO.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+fun box(): String {
+    var x = ""
+    run {
+        x += "O"
+        x += "K"
+    }
+    return x
+}