Revert "[K/N][build] Cleanup obsolete build tasks"

This reverts commit a9cae3fe87.

kotlin-native/backend.native/tests/build.gradle

@@ -212,6 +212,27 @@ task sanity {
     dependsOn(":kotlin-native-shared:check")
 }
 
+// Collect reports in one json.
+task resultsTask() {
+    doLast {
+        def statistics = new Statistics()
+
+        tasks.withType(KonanGTest).matching { it.state.executed }.each {
+            statistics.add(it.statistics)
+        }
+
+        ExternalReportUtilsKt.saveReport("$testOutputExternal/reports.json", statistics)
+        use(KonanTestSuiteReportKt) {
+            project.logger.quiet("DONE.\n\n" +
+                    "TOTAL: $statistics.total\n" +
+                    "PASSED: $statistics.passed\n" +
+                    "FAILED: $statistics.failed\n" +
+                    (statistics.error != 0 ? "ERROR: $statistics.error\n" : "") +
+                    "SKIPPED: $statistics.skipped")
+        }
+    }
+}
+
 boolean isExcluded(String dir) {
     // List of tests that fail due to unresolved compiler bugs
     def excluded = [ ]
@@ -312,6 +333,16 @@ Task dynamicTest(String name, Closure<KonanDynamicTest> configureClosure) {
     }
 }
 
+task slackReport(type:Reporter) {
+    reportHome = rootProject.file("test.output").absoluteFile
+}
+
+task slackReportNightly(type:NightlyReporter) {
+    externalMacosReport = "external_macos_results/reports.json"
+    externalLinuxReport = "external_linux_results/reports.json"
+    externalWindowsReport = "external_windows_results/reports.json"
+}
+
 linkTest("localDelegatedPropertyLink") {
     source = "lower/local_delegated_property_link/main.kt"
     lib = "lower/local_delegated_property_link/lib.kt"
@@ -6093,6 +6124,8 @@ KotlinNativeTestKt.createTest(project, 'harmonyRegexTest', KonanGTest) { task ->
             extraOpts project.globalTestArgs
         }
     }
+
+    task.finalizedBy("resultsTask")
 }
 
 if (UtilsKt.getTestTargetSupportsCodeCoverage(project)) {