Tighten java annot value parsing (#21650)

compiler/src/dotty/tools/dotc/parsing/JavaParsers.scala

@@ -369,8 +369,8 @@ object JavaParsers {
     def annotation(): Option[Tree] = {
       def classOrId(): Tree =
         val id = qualId()
-        if in.lookaheadToken == CLASS then
-          in.nextToken()
+        if in.token == DOT && in.lookaheadToken == CLASS then
+          accept(DOT)
           accept(CLASS)
           TypeApply(
             Select(

tests/pos/i20026/J.java

@@ -0,0 +1,4 @@
+package p;
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class J { }

tests/pos/i20026/S.scala

@@ -0,0 +1 @@
+class S

tests/pos/i20026/TestInstance.java

@@ -0,0 +1,15 @@
+package p;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Inherited
+public @interface TestInstance {
+    enum Lifecycle { PER_CLASS, PER_METHOD; }
+    Lifecycle value();
+}