Java: Add integration test for constant expr detection

Author: IdrissRio

java/ql/integration-tests/java/evaluation-to-constant-errortype/ConstantExpAppearsNonConstant.expected

@@ -0,0 +1 @@
+| Test.java:3:8:3:15 | <TypeAccess of ErrorType> | Expression always evaluates to the same value. |

java/ql/integration-tests/java/evaluation-to-constant-errortype/ConstantExpAppearsNonConstant.qlref

@@ -0,0 +1 @@
+Likely Bugs/Arithmetic/ConstantExpAppearsNonConstant.ql

java/ql/integration-tests/java/evaluation-to-constant-errortype/Test.java

@@ -0,0 +1,7 @@
+class Test {
+  public static void updateFlashlights(Minecraft mc){
+    if(mc.world != null){
+
+    }
+   }
+}

java/ql/integration-tests/java/evaluation-to-constant-errortype/test.py

@@ -0,0 +1,2 @@
+def test(codeql, java):
+    codeql.database.create(build_mode="none")