[IDE] Skip complex closures while checking pattern bindings

This preserves previous behavior where multi-statement closures
where always type-checked without context.

Author: xedin

include/swift/Sema/IDETypeChecking.h

@@ -47,7 +47,8 @@ namespace swift {
   struct PrintOptions;
 
   /// Typecheck binding initializer at \p bindingIndex.
-  void typeCheckPatternBinding(PatternBindingDecl *PBD, unsigned bindingIndex);
+  void typeCheckPatternBinding(PatternBindingDecl *PBD, unsigned bindingIndex,
+                               bool leaveClosureBodiesUnchecked);
 
   /// Check if T1 is convertible to T2.
   ///

lib/IDE/ExprContextAnalysis.cpp

@@ -98,7 +98,8 @@ void swift::ide::typeCheckContextAt(DeclContext *DC, SourceLoc Loc) {
             [](VarDecl *VD) { (void)VD->getInterfaceType(); });
         if (PBD->getInit(i)) {
           if (!PBD->isInitializerChecked(i))
-            typeCheckPatternBinding(PBD, i);
+            typeCheckPatternBinding(PBD, i,
+                                    /*LeaveClosureBodyUnchecked=*/true);
         }
       }
     } else if (auto *defaultArg = dyn_cast<DefaultArgumentInitializer>(DC)) {