wip: fix unsafe seq support

Author: elsakeirouz

lib/AST/ASTWalker.cpp

@@ -2101,14 +2101,13 @@ Stmt *Traversal::visitForEachStmt(ForEachStmt *S) {
       return nullptr;
   }
 
-  if (Stmt *Desugared= S->getDesugaredStmt()) {
+  if (Stmt *Desugared = S->getDesugaredStmt()) {
     if ((Desugared = doIt(Desugared)))
       S->setDesugaredStmt(cast<BraceStmt>(Desugared));
     else
       return nullptr;
   }
 
-
   return S;
 }
 

lib/Sema/TypeCheckStmt.cpp

@@ -3497,7 +3497,7 @@ static BraceStmt *desugarForEachStmt(ForEachStmt* stmt){
   // expr. We need to investigate this.
   // Swap in the 'unsafe' expression.
   if (unsafeExpr) {
-    unsafeExpr->setSubExpr(makeIteratorCall);
+    unsafeExpr = UnsafeExpr::createImplicit(ctx, unsafeExpr->getUnsafeLoc(), makeIteratorCall);
     makeIteratorCall = unsafeExpr;
   }