Fix missing semantic highlighting in attributes and ExtractExitentialValueExpr. (#2541)

* Fix missing semantic highlighting in attributes and ExtractExitentialValueExpr.

* Fix regression on partially specialized generic expr highlighting.

* Add regression test.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/source/slang/slang-ast-support-types.cpp b/source/slang/slang-ast-support-types.cpp
index b550eaa68..aa0513569 100644
--- a/source/slang/slang-ast-support-types.cpp
+++ b/source/slang/slang-ast-support-types.cpp
@@ -57,9 +57,9 @@ Expr* getInnerMostExprFromHigherOrderExpr(Expr* expr)
 UnownedStringSlice getHigherOrderOperatorName(HigherOrderInvokeExpr* expr)
 {
     if (as<ForwardDifferentiateExpr>(expr))
-        return UnownedStringSlice("fwd_diff");
+        return UnownedStringSlice("__fwd_diff");
     else if (as<BackwardDifferentiateExpr>(expr))
-        return UnownedStringSlice("bwd_diff");
+        return UnownedStringSlice("__bwd_diff");
     return UnownedStringSlice();
 }
 }