Light analysis tests: do not render empty lines between classes and in the beginning

compiler/testData/codegen/light-analysis/builtinStubMethods/customReadOnlyIterator.txt

@@ -19,12 +19,10 @@ public final class A {
     public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }
 
-
 public final class CustomReadOnlyIteratorKt {
     public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
 }
 
-
 public final class MyIterator {
     public final static field INSTANCE: MyIterator
     private method <init>(): void