Improve a reported message if -jdk-home path does not exist.

Fix KT-18794

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -407,6 +407,10 @@ class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
 
                 val (jdkHome, classesRoots) = if (arguments.jdkHome != null) {
                     val jdkHome = File(arguments.jdkHome)
+                    if (!jdkHome.exists()) {
+                        messageCollector.report(ERROR, "JDK home directory does not exist: $jdkHome")
+                        return COMPILATION_ERROR
+                    }
                     messageCollector.report(LOGGING, "Using JDK home directory $jdkHome")
                     jdkHome to PathUtil.getJdkClassesRoots(jdkHome)
                 }

compiler/testData/cli/jvm/jdkPathDoesNotExist.args

@@ -0,0 +1,5 @@
+$TESTDATA_DIR$/simple.kt
+-d
+$TEMP_DIR$
+-jdk-home
+$TESTDATA_DIR$/abacaba

compiler/testData/cli/jvm/jdkPathDoesNotExist.out

@@ -0,0 +1,2 @@
+error: JDK home directory does not exist: compiler/testData/cli/jvm/abacaba
+COMPILATION_ERROR

compiler/tests/org/jetbrains/kotlin/cli/CliTestGenerated.java

@@ -224,6 +224,12 @@ public class CliTestGenerated extends AbstractCliTest {
             doJvmTest(fileName);
         }
 
+        @TestMetadata("jdkPathDoesNotExist.args")
+        public void testJdkPathDoesNotExist() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/jvm/jdkPathDoesNotExist.args");
+            doJvmTest(fileName);
+        }
+
         @TestMetadata("jvm8Target.args")
         public void testJvm8Target() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/cli/jvm/jvm8Target.args");