These were declared in the `Opcode` struct type, but were never assigned.
They're not actually used by the language server, but I reused this go schema package for a local experiment and found they were missing.
Supports:
* Syntax highlighting.
* Red squiggles for parse errors.
* Basic sanity checking of operand types.
* Jump to definition of id.
* Find all uses of id.
* Rename id.
* Hover definition of id.
* Format file.
The utils/vscode/src/lsp directory contains code forked from https://github.com/golang/tools/tree/master/internal/lsp.
This code has been modified to remove additional, unneeded features and dependencies.
Submitted on behalf of a third-party: The Go Authors
