Adjust task output detection for Gradle 4.9

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/BaseGradleIT.kt

@@ -4,6 +4,7 @@ import com.intellij.testFramework.TestDataFile
 import org.gradle.api.logging.LogLevel
 import org.gradle.tooling.GradleConnector
 import org.gradle.util.GradleVersion
+import org.intellij.lang.annotations.Language
 import org.jdom.Element
 import org.jdom.input.SAXBuilder
 import org.jdom.output.Format
@@ -537,11 +538,18 @@ abstract class BaseGradleIT {
     }
 
     fun CompiledProject.getOutputForTask(taskName: String): String {
-        val taskOutputRegex = ("(?:\\[LIFECYCLE] \\[class org\\.gradle(?:\\.internal\\.buildevents)?\\.TaskExecutionLogger] :$taskName|" +
-                "\\[org\\.gradle\\.execution\\.plan\\.DefaultPlanExecutor\\] :$taskName.*?started)" +
-                "([\\s\\S]+?)" +
-                "(?:Finished executing task ':$taskName'|" +
-                "\\[org\\.gradle\\.execution\\.plan\\.DefaultPlanExecutor\\] :$taskName.*?completed)").toRegex()
+        @Language("RegExp")
+        val taskOutputRegex = """
+(?:
+\[LIFECYCLE] \[class org\.gradle(?:\.internal\.buildevents)?\.TaskExecutionLogger] :$taskName|
+\[org\.gradle\.execution\.(?:plan|taskgraph)\.Default(?:Task)?PlanExecutor] :$taskName.*?started
+)
+([\s\S]+?)
+(?:
+Finished executing task ':$taskName'|
+\[org\.gradle\.execution\.(?:plan|taskgraph)\.Default(?:Task)?PlanExecutor] :$taskName.*?completed
+)
+""".trimIndent().replace("\n", "").toRegex()
 
         return taskOutputRegex.find(output)?.run { groupValues[1] } ?: error("Cannot find output for task $taskName")
     }