Optimize const vals by inlining them at use sites

#KT-11734 Fixed
 #KT-13570 Fixed

compiler/testData/codegen/bytecodeText/when/simpleConstValsInsideWhen.kt

@@ -0,0 +1,16 @@
+const val A = 10
+private const val B = 20
+
+object Constants {
+    const val C = 30
+}
+
+fun foo(state: Int) {
+    when (state) {
+        A -> return
+        B -> return
+        else -> return
+    }
+}
+
+// 1 LOOKUPSWITCH