Improve generics of DistributedQueryRunner.Builder

Now chains of configuration methods do not erase the builder type.
This allows e.g. for HiveQueryRunner.Builder's method to be invoked before or
after methods coming from DistributedQueryRunner.Builder, without any
compiler issues.

Author: findepi

plugin/trino-hive/src/test/java/io/trino/plugin/hive/HiveQueryRunner.java

@@ -83,17 +83,28 @@ public static QueryRunner create()
         return builder().build();
     }
 
-    public static Builder<Builder<?>> builder()
+    public static ConcreteBuilder builder()
     {
-        return new Builder<>();
+        return new ConcreteBuilder();
     }
 
-    public static Builder<Builder<?>> builder(Session defaultSession)
+    public static ConcreteBuilder builder(Session defaultSession)
     {
-        return new Builder<>(defaultSession);
+        return new ConcreteBuilder(defaultSession);
     }
 
-    public static class Builder<SELF extends Builder<?>>
+    public static final class ConcreteBuilder
+            extends Builder<ConcreteBuilder>
+    {
+        private ConcreteBuilder() {}
+
+        private ConcreteBuilder(Session defaultSession)
+        {
+            super(defaultSession);
+        }
+    }
+
+    public static class Builder<SELF extends Builder<SELF>>
             extends DistributedQueryRunner.Builder<SELF>
     {
         private boolean skipTimezoneSetup;

testing/trino-testing/src/main/java/io/trino/testing/DistributedQueryRunner.java

@@ -732,7 +732,7 @@ private static void closeUnchecked(AutoCloseable closeable)
         }
     }
 
-    public static class Builder<SELF extends Builder<?>>
+    public static class Builder<SELF extends Builder<SELF>>
     {
         private Session defaultSession;
         private boolean withTracing;