Forbid suspension points in critical sections

#KT-26480: Fixed

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

@@ -1037,6 +1037,7 @@ public interface Errors {
     DiagnosticFactory0<KtDeclaration> OVERRIDE_BY_INLINE = DiagnosticFactory0.create(WARNING, DECLARATION_SIGNATURE);
     DiagnosticFactory0<PsiElement> REIFIED_TYPE_PARAMETER_IN_OVERRIDE = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<PsiElement, CallableDescriptor> INLINE_CALL_CYCLE = DiagnosticFactory1.create(ERROR, DEFAULT);
+    DiagnosticFactory1<PsiElement, CallableDescriptor> SUSPENSION_POINT_INSIDE_MONITOR = DiagnosticFactory1.create(ERROR, DEFAULT);
     DiagnosticFactory0<PsiElement> NON_LOCAL_RETURN_IN_DISABLED_INLINE = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtDeclaration> INLINE_PROPERTY_WITH_BACKING_FIELD = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE);
     DiagnosticFactory0<KtAnnotationEntry> NON_INTERNAL_PUBLISHED_API = DiagnosticFactory0.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -934,6 +934,7 @@ public class DefaultErrorMessages {
         //Inline non locals
         MAP.put(NON_LOCAL_RETURN_NOT_ALLOWED, "Can''t inline ''{0}'' here: it may contain non-local returns. Add ''crossinline'' modifier to parameter declaration ''{0}''", ELEMENT_TEXT);
         MAP.put(INLINE_CALL_CYCLE, "The ''{0}'' invocation is a part of inline cycle", NAME);
+        MAP.put(SUSPENSION_POINT_INSIDE_MONITOR, "The ''{0}'' suspension point is inside a critical section", NAME);
         MAP.put(NON_LOCAL_RETURN_IN_DISABLED_INLINE, "Non-local returns are not allowed with inlining disabled");
         MAP.put(NON_LOCAL_SUSPENSION_POINT, "Suspension functions can be called only within coroutine body");
         MAP.put(ILLEGAL_SUSPEND_FUNCTION_CALL, "Suspend function ''{0}'' should be called only from a coroutine or another suspend function", NAME);