IR: create more temporary vals when optimizing tailrec calls

This is needed so that SharedVariablesLowering doesn't get confused, and
SharedVariablesLowering should run after TailrecLowering to properly
optimize tailrec calls in inline lambdas.

compiler/testData/codegen/box/defaultArguments/kt36853a.kt

@@ -1,5 +1,3 @@
-// IGNORE_BACKEND: JS_IR
-
 tailrec fun tailrecDefault(fake: Int, fn: () -> String = { "OK" }): String {
     return if (fake == 0)
         tailrecDefault(1)