Minor: print subprocess output immediately in tests

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/util/gradleRunningUtils.kt

@@ -28,11 +28,14 @@ fun runProcess(cmd: List<String>, workingDir: File): ProcessRunResult {
 
     val process = builder.start()
     // important to read inputStream, otherwise the process may hang on some systems
-    val output = process.inputStream!!.bufferedReader().readText()
-    System.out.println(output)
+    val sb = StringBuilder()
+    process.inputStream!!.bufferedReader().forEachLine {
+        System.out.println(it)
+        sb.appendln(it)
+    }
     val exitCode = process.waitFor()
 
-    return ProcessRunResult(cmd, workingDir, exitCode, output)
+    return ProcessRunResult(cmd, workingDir, exitCode, sb.toString())
 }
 
 fun createGradleCommand(tailParameters: List<String>): List<String> {