[llvm] [IR2Vec] Refactor vocabulary to use canonical type IDs (PR #155323)

[S. VenkataKeerthy via llvm-commits]

================
@@ -162,8 +162,8 @@ class IR2VecTool {
 
     for (const BasicBlock &BB : F) {
       for (const auto &I : BB.instructionsWithoutDebug()) {
----------------
svkeerthy wrote:

Yes, it makes sense. Will track it separately.

https://github.com/llvm/llvm-project/pull/155323