HHH-16616 Apply discriminator by pruning table group

Also, only apply the discriminator for loads since in queries the pruning is already handled by the entity name usage logic.

hibernate-core/src/main/java/org/hibernate/persister/collection/OneToManyPersister.java

@@ -300,6 +300,9 @@ public class OneToManyPersister extends AbstractCollectionPersister {
 			SqlAstCreationState astCreationState) {
 		super.applyWhereFragments( predicateConsumer, alias, tableGroup, astCreationState );
 
+		if ( !astCreationState.supportsEntityNameUsage() ) {
+			// We only need to apply discriminator for loads, since queries with joined
+			// inheritance subtypes are already filtered by the entity name usage logic
 			getElementPersisterInternal().applyDiscriminator(
 					predicateConsumer,
 					alias,
@@ -307,6 +310,7 @@ public class OneToManyPersister extends AbstractCollectionPersister {
 					astCreationState
 			);
 		}
+	}
 
 	@Override
 	public FilterAliasGenerator getFilterAliasGenerator(String rootAlias) {

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -14,6 +14,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.IdentityHashMap;
@@ -3013,7 +3014,7 @@ public abstract class AbstractEntityPersister
 			TableGroup tableGroup,
 			SqlAstCreationState creationState) {
 		if ( needsDiscriminator() ) {
-			predicateConsumer.accept( createDiscriminatorPredicate( alias, tableGroup, creationState ) );
+			pruneForSubclasses( tableGroup, Collections.singletonMap( getEntityName(), EntityNameUse.TREAT ) );
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/query/sqm/sql/BaseSqmToSqlAstConverter.java

@@ -3042,6 +3042,11 @@ public abstract class BaseSqmToSqlAstConverter<T extends Statement> extends Base
 		}
 	}
 
+	@Override
+	public boolean supportsEntityNameUsage() {
+		return true;
+	}
+
 	@Override
 	public void registerEntityNameUsage(
 			TableGroup tableGroup,

hibernate-core/src/main/java/org/hibernate/sql/ast/spi/SqlAstCreationState.java

@@ -42,4 +42,9 @@ public interface SqlAstCreationState {
 			String hibernateEntityName) {
 		// No-op
 	}
+
+	@Internal
+	default boolean supportsEntityNameUsage() {
+		return false;
+	}
 }

hibernate-core/src/main/java/org/hibernate/sql/ast/tree/from/NamedTableReference.java

@@ -72,7 +72,7 @@ public class NamedTableReference extends AbstractTableReference {
 
 	@Override
 	public boolean containsAffectedTableName(String requestedName) {
-		return isEmpty( requestedName ) || getTableExpression().equals( requestedName );
+		return isEmpty( requestedName ) || getTableExpression().contains( requestedName );
 	}
 
 	@Override