[clang] [HLSL] Add ByteAddressBuffer definition to HLSLExternalSemaSource #113477 (PR #116699)

[Helena Kotas via cfe-commits]

================
@@ -67,6 +67,7 @@ struct BuiltinTypeDeclBuilder {
     Record = CXXRecordDecl::Create(AST, TagDecl::TagKind::Class, HLSLNamespace,
                                    SourceLocation(), SourceLocation(), &II,
                                    PrevDecl, true);
+    Record->startDefinition();
----------------
hekota wrote:

We should not be starting the definition here - this constructor just creates the declaration.

https://github.com/llvm/llvm-project/pull/116699