Add codegen box test templates for identifiers

compiler/tests-spec/testData/codegen/box/templates/identifiers/infixFunctionCall.kt

@@ -0,0 +1,12 @@
+infix fun Int.<!ELEMENT(1)!>(value: Int) = value > 100
+
+infix fun Int.<!ELEMENT(2)!>(value: Int): Int {
+    return value - 90
+}
+
+fun box(): String? {
+    if (1 + 1 <!ELEMENT(1)!> -1001020) return null
+    if (1 + 1 <!ELEMENT(2)!> 2004 <!ELEMENT(1)!> -0) return null
+
+    return "OK"
+}