[llvm] Refactoring llvm-ir2vec.cpp for better separation of concerns in the Tooling classes (PR #170078)

[S. VenkataKeerthy via llvm-commits]

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@@ -216,56 +222,139 @@ class IR2VecTool {
         unsigned Opcode = Vocabulary::getIndex(I.getOpcode());
         unsigned TypeID = Vocabulary::getIndex(I.getType()->getTypeID());
 
-        // Add "Next" relationship with previous instruction
         if (HasPrevOpcode) {
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svkeerthy wrote:

Please retain the comments here and below. They can be removed/cleaned up if they are not appropriate. 

https://github.com/llvm/llvm-project/pull/170078