Scripting: switch legacy CLI REPL to the new infrastructure

libraries/scripting/jvm/src/kotlin/script/experimental/jvm/BasicJvmReplEvaluator.kt

@@ -57,8 +57,13 @@ class BasicJvmReplEvaluator(val scriptEvaluator: ScriptEvaluator = BasicJvmScrip
                 }
                 KJvmEvaluatedSnippet(snippetVal, currentConfiguration, retVal)
             }
-            else ->
-                KJvmEvaluatedSnippet(snippetVal, currentConfiguration, ResultValue.NotEvaluated)
+            else -> {
+                val firstError = evalRes.reports.find { it.isError() }
+                KJvmEvaluatedSnippet(
+                    snippetVal, currentConfiguration,
+                    firstError?.exception?.let { ResultValue.Error(it) } ?: ResultValue.NotEvaluated
+                )
+            }
         }
 
         val newNode = lastEvaluatedSnippet.add(newEvalRes)

libraries/scripting/jvm/src/kotlin/script/experimental/jvm/util/runtimeExceptionReporting.kt

@@ -5,6 +5,7 @@
 
 package kotlin.script.experimental.jvm.util
 
+import java.io.ByteArrayOutputStream
 import java.io.PrintStream
 import kotlin.script.experimental.api.ResultValue
 
@@ -42,3 +43,11 @@ fun ResultValue.Error.renderError(stream: PrintStream) {
         }
     }
 }
+
+fun ResultValue.Error.renderError(): String =
+    ByteArrayOutputStream().use { os ->
+        val ps = PrintStream(os)
+        renderError(ps)
+        ps.flush()
+        os.toString()
+    }