AST: Remove stray assert

A pack archetype from an outer expansion here is treated as a scalar.

Author: slavapestov

lib/AST/ParameterPack.cpp

@@ -307,8 +307,6 @@ static CanPackType getReducedShapeOfPack(const ASTContext &ctx,
     }
 
     // Use () as a placeholder for scalar shape.
-    assert(!elt->template is<PackArchetypeType>() &&
-           "Pack archetype outside of a pack expansion");
     elts.push_back(ctx.TheEmptyTupleType);
   }
 

test/IRGen/pack_metadata_dealloc.swift

@@ -18,4 +18,13 @@ func f<each T: P>(_ t: repeat each T) -> (repeat (each T).A) {
 // CHECK-NOT: call ptr llvm.stacksave.p0()
 // CHECK:  call void @llvm.stackrestore.p0(ptr [[SPSAVE2]])
 // CHECK:  call void @llvm.stackrestore.p0(ptr [[SPSAVE1]])
-// CHECK:  ret void
+// CHECK:  ret void
+
+struct G<each T> {
+  init(_: repeat each T) {}
+}
+
+func f2<each T: P, each U>(t: repeat each T, u: repeat each U) async -> (repeat G<(each T).A, repeat each U>) {
+  let x = (repeat G((each t).a, repeat each u))
+  return x
+}