Polish build

Issue: SPR-15885

Author: bclozel

build.gradle

@@ -91,20 +91,17 @@ configure(allprojects) { project ->
 		resolutionStrategy.cacheChangingModulesFor 0, 'seconds'
 	}
 
-	compileJava.options*.compilerArgs = [
-		"-Xlint:serial", "-Xlint:varargs", "-Xlint:cast", "-Xlint:classfile",
-		"-Xlint:dep-ann", "-Xlint:divzero", "-Xlint:empty", "-Xlint:finally",
-		"-Xlint:overrides", "-Xlint:path", "-Xlint:processing", "-Xlint:static",
-		"-Xlint:try", "-Xlint:fallthrough", "-Xlint:rawtypes", "-Xlint:deprecation",
-		"-Xlint:unchecked", "-Xlint:-options", "-Werror"
-	]
-
-	compileTestJava.options*.compilerArgs = [
-		"-Xlint:serial", "-Xlint:-varargs", "-Xlint:cast", "-Xlint:classfile",
-		"-Xlint:dep-ann", "-Xlint:divzero", "-Xlint:empty", "-Xlint:finally",
-		"-Xlint:overrides", "-Xlint:path", "-Xlint:processing", "-Xlint:static",
-		"-Xlint:try", "-Xlint:-fallthrough", "-Xlint:-rawtypes", "-Xlint:-deprecation",
-		"-Xlint:-unchecked", "-Xlint:-options"]
+	def compilerArgs = [
+			"-Xlint:serial", "-Xlint:varargs", "-Xlint:cast", "-Xlint:classfile",
+			"-Xlint:dep-ann", "-Xlint:divzero", "-Xlint:empty", "-Xlint:finally",
+			"-Xlint:overrides", "-Xlint:path", "-Xlint:processing", "-Xlint:static",
+			"-Xlint:try", "-Xlint:fallthrough", "-Xlint:rawtypes", "-Xlint:deprecation",
+			"-Xlint:unchecked", "-Xlint:-options"
+			]
+
+	compileJava.options*.compilerArgs = compilerArgs + "-Werror"
+
+	compileTestJava.options*.compilerArgs = compilerArgs
 
 	compileJava {
 		sourceCompatibility = 1.8
@@ -128,7 +125,7 @@ configure(allprojects) { project ->
 		// classes with the "$" pattern; otherwise, using -Dtest.single=MyTests to
 		// run MyTests by itself will fail if MyTests contains any inner classes.
 		exclude(["**/Abstract*.class", '**/*$*'])
-		reports.junitXml.destination = file("$buildDir/test-results")
+		reports.junitXml.setDestination(file("$buildDir/test-results"))
 	}
 
 	repositories {
@@ -244,12 +241,6 @@ configure(rootProject) {
 		applyMavenExclusions = false
 	}
 
-	// TODO: DetectSplitPackagesPlugin fails in line 154 due to method not found on java.io.File.
-	// TODO: Possibly related to user rights or OS differences; passes on local Windows machine.
-	// detectSplitPackages {
-	//	projectsToScan -= project(":spring-instrument-tomcat")
-	// }
-
 	// don't publish the default jar for the root project
 	configurations.archives.artifacts.clear()