Minor, fix appendln deprecation warnings in cli

Can't use appendLine yet because this module is compiled with API
version 1.3.

compiler/cli/src/org/jetbrains/kotlin/cli/common/CommonCompilerPerformanceManager.kt

@@ -137,8 +137,8 @@ abstract class CommonCompilerPerformanceManager(private val presentableName: Str
     }
 
     private fun createPerformanceReport(): ByteArray = buildString {
-        appendln("$presentableName performance report")
-        measurements.map { it.render() }.sorted().forEach { appendln(it) }
+        append("$presentableName performance report\n")
+        measurements.map { it.render() }.sorted().forEach { append("$it\n") }
     }.toByteArray()
 
     open fun notifyRepeat(total: Int, number: Int) {}

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/JvmRuntimeVersionsConsistencyChecker.kt

@@ -240,9 +240,9 @@ object JvmRuntimeVersionsConsistencyChecker {
         if (oldestVersion == newestVersion) return oldestVersion
 
         messageCollector.issue(null, buildString {
-            appendln("Runtime JAR files in the classpath should have the same version. These files were found in the classpath:")
+            append("Runtime JAR files in the classpath should have the same version. These files were found in the classpath:\n")
             for (jar in jars) {
-                appendln("    ${jar.file.path} (version ${jar.version})")
+                append("    ${jar.file.path} (version ${jar.version})\n")
             }
         }.trimEnd())