Add semantic tag for unresolved references

This is a quick way to implement unresolved reference diagnostics.
For example, adding to VS Code config

    "editor.tokenColorCustomizationsExperimental": {
        "unresolvedReference": "#FF0000"
    },

will highlight all unresolved refs in red.

1 files changed, 4 insertions, 0 deletions

diff --git a/editors/code/package.json b/editors/code/package.json
index 5ce59e54a..79410ad10 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -517,6 +517,10 @@
                 "id": "union",
                 "description": "Style for C-style untagged unions",
                 "superType": "type"
+            },
+            {
+                "id": "unresolvedReference",
+                "description": "Style for names which can not be resolved due to compilation errors"
             }
         ],
         "semanticTokenModifiers": [