[clang] [PAC][clang] Implement address/type discrimination for VTT vtable pointers (PR #205808)

[Oliver Hunt via cfe-commits]

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@@ -121,20 +122,38 @@ CGPointerAuthInfo CodeGenFunction::EmitPointerAuthInfo(
   if (!Schema)
     return CGPointerAuthInfo();
 
-  llvm::Value *Discriminator =
-      CGM.getPointerAuthOtherDiscriminator(Schema, SchemaDecl, SchemaType);
+  llvm::ConstantInt *Discriminator =
+      Schema.getOtherDiscrimination() == PointerAuthSchema::Discrimination::None
+          ? nullptr
+          : CGM.getPointerAuthOtherDiscriminator(Schema, SchemaDecl,
+                                                 SchemaType);
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ojhunt wrote:

This should not be necessary -- `getPointerAuthOtherDiscriminator` already handles the `PointerAuthSchema::Discrimination::None` case

https://github.com/llvm/llvm-project/pull/205808