Annotation repetition checking with a pair of tests, some old tests changes

compiler/testData/diagnostics/tests/annotations/options/unrepeatable.kt

@@ -0,0 +1,13 @@
+annotation(repeatable = false) class unrepann(val x: Int)
+
+annotation class ann(val y: Int)
+
+unrepann(1) <!REPEATED_ANNOTATION!>unrepann(2)<!> class DoubleAnnotated
+
+ann(3) <!REPEATED_ANNOTATION!>ann(7)<!> <!REPEATED_ANNOTATION!>ann(42)<!> class TripleAnnotated
+
+target(AnnotationTarget.EXPRESSION) annotation class annexpr
+
+ann(0) <!REPEATED_ANNOTATION!>ann(1)<!> fun foo(@ann(7) <!REPEATED_ANNOTATION!>@ann(2)<!> x: Int): Int {
+    @annexpr <!REPEATED_ANNOTATION!>@annexpr<!> return x
+}