Generating SAM wrapper class per source file.

compiler/testData/codegen/boxMultiFile/samWrappersDifferentFiles/1/wrapped.kt

@@ -0,0 +1,4 @@
+fun getWrapped1(): Runnable {
+  val f = { }
+  return Runnable(f)
+}

compiler/testData/codegen/boxMultiFile/samWrappersDifferentFiles/2/wrapped.kt

@@ -0,0 +1,4 @@
+fun getWrapped2(): Runnable {
+  val f = { }
+  return Runnable(f)
+}

compiler/testData/codegen/boxMultiFile/samWrappersDifferentFiles/box.kt

@@ -0,0 +1,6 @@
+fun box(): String {
+    val class1 = getWrapped1().getClass()
+    val class2 = getWrapped2().getClass()
+
+    return if (class1 != class2) "OK" else "Same class: $class1"
+}