Add `IRThisTypeWitness` to stand in for witness lookups inside an interface definition. (#3316)

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

1 files changed, 10 insertions, 0 deletions

diff --git a/source/slang/slang-ir.h b/source/slang/slang-ir.h
index cb744d4da..8d7cad0b4 100644
--- a/source/slang/slang-ir.h
+++ b/source/slang/slang-ir.h
@@ -1802,6 +1802,16 @@ struct IRThisType : IRType
     }
 };
 
+struct IRThisTypeWitness : IRInst
+{
+    IR_LEAF_ISA(ThisTypeWitness)
+
+    IRInst* getConstraintType()
+    {
+        return getOperand(0);
+    }
+};
+
 struct IRInterfaceRequirementEntry : IRInst
 {
     IRInst* getRequirementKey() { return getOperand(0); }