Make POWER a valid token as an identifier for JPQL and HQL.

See #3143

spring-data-jpa/src/main/antlr4/org/springframework/data/jpa/repository/query/Hql.g4

@@ -812,6 +812,7 @@ reservedWord
 	| PERCENT
 	| PLACING
 	| POSITION
+	| POWER
 	| PRECEDING
 	| QUARTER
 	| RANGE

spring-data-jpa/src/main/antlr4/org/springframework/data/jpa/repository/query/Jpql.g4

@@ -605,6 +605,7 @@ identification_variable
     | NEW
     | ORDER
     | OUTER
+    | POWER
     | FLOOR
     | SIGN
     | TIME

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/HqlQueryRendererTests.java

@@ -1600,4 +1600,9 @@ class HqlQueryRendererTests {
 				ORDER BY j.id
 				""");
 	}
+
+	@Test // GH-3143
+	void powerShouldBeLegalInAQuery() {
+		assertQuery("select e.power.id from MyEntity e");
+	}
 }

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/JpqlQueryRendererTests.java

@@ -983,4 +983,9 @@ class JpqlQueryRendererTests {
 				ORDER BY j.id
 				""");
 	}
+
+	@Test // GH-3143
+	void powerShouldBeLegalInAQuery() {
+		assertQuery("select e.power.id from MyEntity e");
+	}
 }