JVM: report error on -Xjdk-release=6 without -jvm-target

#KT-59098

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

@@ -52,7 +52,15 @@ fun CompilerConfiguration.setupJvmSpecificArguments(arguments: K2JVMCompilerArgu
     }
 
     val jvmTargetValue = when (releaseTargetArg) {
-        "6" -> "1.6"
+        "6", "1.6" -> {
+            if (jvmTargetArg == null) {
+                messageCollector.report(
+                    ERROR,
+                    "'-Xjdk-release=$releaseTargetArg' option requires explicit JVM target. Please specify the '-jvm-target' option"
+                )
+            }
+            jvmTargetArg
+        }
         "8" -> "1.8"
         null -> jvmTargetArg
         else -> releaseTargetArg

compiler/testData/cli/jvm/jdkRelease6WithoutExplicitJvmTarget.args

@@ -0,0 +1,4 @@
+-Xjdk-release=1.6
+$TESTDATA_DIR$/jdkRelease.kt
+-d
+$TEMP_DIR$

compiler/testData/cli/jvm/jdkRelease6WithoutExplicitJvmTarget.out

@@ -0,0 +1,2 @@
+error: '-Xjdk-release=1.6' option requires explicit JVM target. Please specify the '-jvm-target' option
+COMPILATION_ERROR

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

@@ -755,6 +755,11 @@ public class CliTestGenerated extends AbstractCliTest {
       runTest("compiler/testData/cli/jvm/jdkRelease.args");
     }
 
+    @TestMetadata("jdkRelease6WithoutExplicitJvmTarget.args")
+    public void testJdkRelease6WithoutExplicitJvmTarget() {
+      runTest("compiler/testData/cli/jvm/jdkRelease6WithoutExplicitJvmTarget.args");
+    }
+
     @TestMetadata("jdkRelease8.args")
     public void testJdkRelease8() {
       runTest("compiler/testData/cli/jvm/jdkRelease8.args");