Add `none` literal that is convertible to `Optional`. (#2356)

* Add `none` literal that is convertible to `Optional`.

* Fix cpu code gen.

* Include vk and cpu test for is-as operator test.

* Inline comparison operators.

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index aef60c9d9..c7fbfda77 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -3365,6 +3365,11 @@ struct ExprLoweringVisitorBase : ExprVisitor<Derived, LoweredValInfo>
         return LoweredValInfo::simple(context->irBuilder->getPtrValue(nullptr));
     }
 
+    LoweredValInfo visitNoneLiteralExpr(NoneLiteralExpr*)
+    {
+        return LoweredValInfo::simple(context->irBuilder->getVoidValue());
+    }
+
     LoweredValInfo visitIntegerLiteralExpr(IntegerLiteralExpr* expr)
     {
         auto type = lowerType(context, expr->type);