wip: do not use opaque value expr for sequence

Author: elsakeirouz

include/swift/AST/Expr.h

@@ -6724,10 +6724,10 @@ class MacroExpansionExpr final : public Expr,
   }
 };
 
-/// OpaqueExpr - created to serve as an indirection to a ForEachStmt's where
-/// clause to avoid visiting it twice in the ASTWalker after having desugared the
-/// loop. This will only be processed in SILGen to emit the underlying
-/// expression.
+/// OpaqueExpr - created to serve as an indirection to a ForEachStmt's sequence
+/// expr and where clause to avoid visiting it twice in the ASTWalker after
+/// having desugared the loop. This will only be processed in SILGen to emit
+/// the underlying expression.
 class OpaqueExpr final : public Expr {
   Expr *OriginalExpr;
 

include/swift/AST/Stmt.h

@@ -1011,7 +1011,6 @@ class ForEachStmt : public LabeledStmt {
   Expr *nextCall = nullptr;
   BraceStmt *desugaredStmt = nullptr;
   Expr *convertElementExpr = nullptr;
-  OpaqueValueExpr *sequenceExpr = nullptr;
 
 public:
   ForEachStmt(LabeledStmtInfo LabelInfo, SourceLoc ForLoc, SourceLoc TryLoc,

lib/Sema/TypeCheckStmt.cpp

@@ -3486,7 +3486,7 @@ static BraceStmt *desugarForEachStmt(ForEachStmt* stmt){
                                      : ctx.getSequenceMakeIterator();
 
   auto *makeIteratorRef = new (ctx) UnresolvedDotExpr(
-        opaqueSeqExpr->getOriginalExpr(), SourceLoc(), DeclNameRef(makeIterator->getName()),
+        opaqueSeqExpr, SourceLoc(), DeclNameRef(makeIterator->getName()),
         DeclNameLoc(stmt->getForLoc()), /*implicit=*/true);
   makeIteratorRef->setFunctionRefInfo(FunctionRefInfo::singleBaseNameApply());