Fix bug: IgnoreInheritance in lookup (#6146)

* Fix bug: IgnoreInheritance in lookup

When specifying IgnoreInheritance in lookup, it will ignore
all members in the self extension for generic, the reason is
that it doesn't specialize the target type of the extension
decl when comparing with self type, so it will result that every
type is unequal to the target type.

Author: kaizhangNV

source/slang/slang-check-overload.cpp

@@ -2167,15 +2167,16 @@ void SemanticsVisitor::AddTypeOverloadCandidates(Type* type, OverloadResolveCont
     // from a value of the same type. There is no need in Slang for
     // "copy constructors" but the core module currently has to define
     // some just to make code that does, e.g., `float(1.0f)` work.)
-
+    LookupOptions options =
+        LookupOptions(uint8_t(LookupOptions::IgnoreInheritance) | uint8_t(LookupOptions::NoDeref));
     LookupResult initializers = lookUpMember(
         m_astBuilder,
         this,
         getName("$init"),
         type,
         context.sourceScope,
         LookupMask::Default,
-        LookupOptions::NoDeref);
+        options);
 
     AddOverloadCandidates(initializers, context);
 }

source/slang/slang-lookup.cpp

@@ -436,7 +436,7 @@ static void _lookupMembersInSuperTypeFacets(
             continue;
         }
 
-        auto extensionFacet = as<ExtensionDecl>(facet.getImpl()->getDeclRef().getDecl());
+
         // If we are looking up in an interface, and the lookup request told us
         // to skip interfaces, we should do so here.
         if (auto baseInterfaceDeclRef = containerDeclRef.as<InterfaceDecl>())
@@ -448,10 +448,22 @@ static void _lookupMembersInSuperTypeFacets(
         // "Self"
         else if (
             int(request.options) & int(LookupOptions::IgnoreInheritance) &&
-            (facet.getImpl()->directness != Facet::Directness::Self &&
-             (!extensionFacet || !extensionFacet->targetType.type->equals(selfType))))
+            (facet.getImpl()->directness != Facet::Directness::Self))
         {
-            continue;
+            if (auto extensionDeclRef = facet.getImpl()->getDeclRef().as<ExtensionDecl>())
+            {
+                if (auto targetType = getTargetType(astBuilder, extensionDeclRef))
+                {
+                    if (!targetType->equals(selfType))
+                    {
+                        // If the extension is to the same type as the one we are looking up in, we
+                        // should include it in the lookup.
+                        continue;
+                    }
+                }
+            }
+            else
+                continue;
         }
 
         // Some things that are syntactically `InheritanceDecl`s don't actually