Always do stack spilling during inline cause of dex problem

Dex issue: https://issuetracker.google.com/issues/68796377

  #KT-20844 Fixed

compiler/testData/codegen/box/optimizations/kt20844.kt

@@ -0,0 +1,9 @@
+//WITH_RUNTIME
+
+fun foo(x: String, ys: List<String>) =
+        x + ys.fold("", { a, b -> a + b })
+
+var flag = true
+
+fun box(): String =
+        foo("O", if (flag) listOf("k").map { it.toUpperCase() } else listOf())