Reinstate dependency management for hibernate-entitymanager

This commit reinstates dependency management for
hibernate-entitymanager as, while empty, it remains part of Hibernate
5.2.x and people may still have a dependency upon it.

It also reinstates the configuration of skipping the jar during TLD
scanning so that any application that does depend on
hibernate-entitymanager doesn't scan it for TLDs.

See gh-8433

spring-boot-dependencies/pom.xml

@@ -1678,6 +1678,17 @@
 				<artifactId>hibernate-ehcache</artifactId>
 				<version>${hibernate.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.hibernate</groupId>
+				<artifactId>hibernate-entitymanager</artifactId>
+				<version>${hibernate.version}</version>
+				<exclusions>
+					<exclusion>
+						<groupId>xml-apis</groupId>
+						<artifactId>xml-apis</artifactId>
+					</exclusion>
+				</exclusions>
+			</dependency>
 			<dependency>
 				<groupId>org.hibernate</groupId>
 				<artifactId>hibernate-envers</artifactId>

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TldSkipPatterns.java

@@ -86,6 +86,7 @@ final class TldSkipPatterns {
 		patterns.add("ehcache-core-*.jar");
 		patterns.add("hibernate-core-*.jar");
 		patterns.add("hibernate-commons-annotations-*.jar");
+		patterns.add("hibernate-entitymanager-*.jar");
 		patterns.add("hibernate-jpa-2.1-api-*.jar");
 		patterns.add("hibernate-validator-*.jar");
 		patterns.add("hsqldb-*.jar");