KT-52409 Report error when using K2 with multi-platform

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

@@ -104,6 +104,13 @@ object FirKotlinToJvmBytecodeCompiler {
                 return false
             }
         }
+        if (projectConfiguration.languageVersionSettings.supportsFeature(LanguageFeature.MultiPlatformProjects)) {
+            messageCollector.report(
+                CompilerMessageSeverity.ERROR,
+                "K2 compiler does not support multi-platform projects yet, so please remove -Xuse-k2 flag"
+            )
+            return false
+        }
 
         val outputs = ArrayList<Pair<FirResult, GenerationState>>(chunk.size)
         val targetIds = projectConfiguration.get(JVMConfigurationKeys.MODULES)?.map(::TargetId)

compiler/testData/cli/jvm/firMultiplatformCompilationWithError.out

@@ -11,11 +11,5 @@ compiler or generated code. Use it at your own risk!
 warning: ATTENTION!
  This build uses experimental K2 compiler:
   -Xuse-k2
-compiler/testData/cli/jvm/firMultiplatformCompilationWithError/jvm.kt:1:18: error: actual class 'public abstract actual interface A : R|kotlin/Any|' has no corresponding members for expected class members:
-
-    public abstract expect fun foo(): R|kotlin/Unit|
-
-
-actual interface A
-                 ^
+error: k2 compiler does not support multi-platform projects yet, so please remove -Xuse-k2 flag
 COMPILATION_ERROR

compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors.out

@@ -11,4 +11,5 @@ compiler or generated code. Use it at your own risk!
 warning: ATTENTION!
  This build uses experimental K2 compiler:
   -Xuse-k2
-OK
+error: k2 compiler does not support multi-platform projects yet, so please remove -Xuse-k2 flag
+COMPILATION_ERROR