[clang] [CIR] Add support for thread-local storage (TLS) (PR #168662)

[Andy Kaylor via cfe-commits]

================
@@ -440,7 +361,8 @@ CIRGenModule::getOrCreateStaticVarDecl(const VarDecl &d,
   if (supportsCOMDAT() && gv.isWeakForLinker())
     gv.setComdat(true);
 
-  assert(!cir::MissingFeatures::opGlobalThreadLocal());
+  if (d.getTLSKind())
+    llvm_unreachable("TLS mode is NYI");
----------------
andykaylor wrote:

```suggestion
    cgm.errorNYI(d.getSourceRange(), "getOrCreateStaticVarDecl: TLS");
```

https://github.com/llvm/llvm-project/pull/168662