[BuilderTransform] Don't skip multi-statement closures during pre-check

Each of the elements in the result builder has to be fully pre-checked
now that multi-statement inference has been enabled.

Author: xedin

lib/Sema/BuilderTransform.cpp

@@ -1933,7 +1933,7 @@ class PreCheckResultBuilderApplication : public ASTWalker {
 
       HasError |= ConstraintSystem::preCheckExpression(
           E, DC, /*replaceInvalidRefsWithErrors=*/true,
-          /*leaveClosureBodiesUnchecked=*/true);
+          /*leaveClosureBodiesUnchecked=*/false);
 
       HasError |= transaction.hasErrors();