Use specified comparison generator for chars in optimized ranges

Otherwise if Char value is a result of some erased generic call,
coercing it to I (primitive int) causes CCE at run-time.

 #KT-23104 Fixed Target versions 1.2.40

compiler/testData/codegen/box/ranges/contains/genericCharInRangeLiteral.kt

@@ -0,0 +1,7 @@
+class Cell<T>(val value: T)
+
+fun box(): String =
+    if (Cell('a').value in 'a'..'z')
+        "OK"
+    else
+        "fail"