Add ir interpreter tests

compiler/testData/ir/interpreter/generatedStdlib/trim.kt

@@ -0,0 +1,5 @@
+import kotlin.text.*
+
+const val trimmed = "  1  ".<!EVALUATED: `1`!>trim()<!>
+const val trimmedWithPredicate = ("  2  " as CharSequence).trim { it.isWhitespace() }.<!EVALUATED: `2`!>toString()<!>
+const val charSequenceTrim = ("  3  " as CharSequence).trim().<!EVALUATED: `3`!>toString()<!>