Raise deprecations of suspend calls with dangling lambda to error

#KT-22562

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -1176,7 +1176,7 @@ public interface Errors {
     DiagnosticFactory0<PsiElement> ILLEGAL_RESTRICTED_SUSPENDING_FUNCTION_CALL = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<PsiElement> NON_MODIFIER_FORM_FOR_BUILT_IN_SUSPEND = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtReturnExpression> RETURN_FOR_BUILT_IN_SUSPEND = DiagnosticFactory0.create(ERROR);
-    DiagnosticFactory0<PsiElement> MODIFIER_FORM_FOR_NON_BUILT_IN_SUSPEND = DiagnosticFactory0.create(WARNING);
+    DiagnosticFactory0<PsiElement> MODIFIER_FORM_FOR_NON_BUILT_IN_SUSPEND = DiagnosticFactory0.create(ERROR);
 
     DiagnosticFactory1<PsiElement, RenderedDiagnostic<?>> PLUGIN_ERROR = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<PsiElement, RenderedDiagnostic<?>> PLUGIN_WARNING = DiagnosticFactory1.create(WARNING);

libraries/stdlib/test/coroutines/CoroutinesReferenceValuesTest.kt

@@ -37,7 +37,7 @@ class CoroutinesReferenceValuesTest {
 
     @Test
     fun testBadClass() {
-        val bad = suspend {
+        val bad = suspend() {
             checkBadClassTwice()
             getBadClassViaSuspend()
         }