[AST] Store a source location for '.element' in MaterializePackExpr.

Author: hborla

include/swift/AST/Expr.h

@@ -3659,14 +3659,18 @@ class MaterializePackExpr final : public Expr {
   /// The expression from which to materialize a pack.
   Expr *FromExpr;
 
-  MaterializePackExpr(Expr *fromExpr, bool implicit, Type type)
+  /// The source location of \c .element
+  SourceLoc ElementLoc;
+
+  MaterializePackExpr(Expr *fromExpr, SourceLoc elementLoc,
+                      Type type, bool implicit)
       : Expr(ExprKind::MaterializePack, implicit, type),
-        FromExpr(fromExpr) {}
+        FromExpr(fromExpr), ElementLoc(elementLoc) {}
 
 public:
   static MaterializePackExpr *create(ASTContext &ctx, Expr *fromExpr,
-                                     bool implicit = false,
-                                     Type type = Type());
+                                     SourceLoc elementLoc, Type type,
+                                     bool implicit = false);
 
   Expr *getFromExpr() const { return FromExpr; }
 
@@ -3679,7 +3683,7 @@ class MaterializePackExpr final : public Expr {
   }
 
   SourceLoc getEndLoc() const {
-    return FromExpr->getEndLoc();
+    return ElementLoc;
   }
 
   static bool classof(const Expr *E) {

lib/AST/Expr.cpp

@@ -1307,8 +1307,10 @@ PackElementExpr::create(ASTContext &ctx, SourceLoc eachLoc, Expr *packRefExpr,
 
 MaterializePackExpr *
 MaterializePackExpr::create(ASTContext &ctx, Expr *fromExpr,
-                            bool implicit, Type type) {
-  return new (ctx) MaterializePackExpr(fromExpr, implicit, type);
+                            SourceLoc elementLoc,
+                            Type type, bool implicit) {
+  return new (ctx) MaterializePackExpr(fromExpr, elementLoc,
+                                       type, implicit);
 }
 
 SequenceExpr *SequenceExpr::create(ASTContext &ctx, ArrayRef<Expr*> elements) {

lib/Sema/CSApply.cpp

@@ -3415,10 +3415,10 @@ namespace {
       }
 
       case OverloadChoiceKind::MaterializePack: {
-        auto packType = simplifyType(cs.getType(expr));
+        auto packType = solution.getResolvedType(expr);
         return cs.cacheType(
             MaterializePackExpr::create(cs.getASTContext(),
-                                        base, /*implicit=*/false,
+                                        base, expr->getEndLoc(),
                                         packType));
       }