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, 6 insertions, 0 deletions

diff --git a/source/slang/slang-check-expr.cpp b/source/slang/slang-check-expr.cpp
index 714eba9a3..cb75e3078 100644
--- a/source/slang/slang-check-expr.cpp
+++ b/source/slang/slang-check-expr.cpp
@@ -822,6 +822,12 @@ namespace Slang
         return expr;
     }
 
+    Expr* SemanticsExprVisitor::visitNoneLiteralExpr(NoneLiteralExpr* expr)
+    {
+        expr->type = m_astBuilder->getNoneType();
+        return expr;
+    }
+
     Expr* SemanticsExprVisitor::visitIntegerLiteralExpr(IntegerLiteralExpr* expr)
     {
         // The expression might already have a type, determined by its suffix.