delete two unused impl classes and an unused type param

Author: gavinking

hibernate-core/src/main/java/org/hibernate/query/internal/DelegatingDomainQueryExecutionContext.java

@@ -16,7 +16,7 @@
 public class DelegatingDomainQueryExecutionContext implements DomainQueryExecutionContext {
 	private final DomainQueryExecutionContext delegate;
 
-	public <R> DelegatingDomainQueryExecutionContext(DomainQueryExecutionContext delegate) {
+	public DelegatingDomainQueryExecutionContext(DomainQueryExecutionContext delegate) {
 		this.delegate = delegate;
 	}