Improve test data format for SMAP codegen tests

Instead of comments in a Kotlin source file, add a .smap with the contents of
the source mapping data (and possible comments)

compiler/testData/codegen/boxInline/smap/resolve/inlineIterator.kt

@@ -6,8 +6,6 @@ public class A(val p: Int)
 
 operator inline fun A.iterator() = (1..p).iterator()
 
-//SMAP ABSENT
-
 // FILE: 2.kt
 
 import zzz.*
@@ -21,16 +19,20 @@ fun box(): String {
     return if (p == 15) "OK" else "fail: $p"
 }
 
-//SMAP
-//inlineIterator.1.kt
-//Kotlin
-//*S Kotlin
-//*F
-//+ 1 inlineIterator.1.kt
-//InlineIterator_1Kt
-//+ 2 inlineIterator.2.kt
-//zzz/InlineIterator_2Kt
-//*L
-//1#1,24:1
-//5#2:25
-//*E
+// FILE: 1.smap
+
+// FILE: 2.smap
+
+SMAP
+2.kt
+Kotlin
+*S Kotlin
+*F
++ 1 2.kt
+_2Kt
++ 2 1.kt
+zzz/_1Kt
+*L
+1#1,14:1
+7#2:15
+*E