llama-vocab: replace postfix with prefix increment for iterators

[GermanAizek]

For custom iterator types, such as those often found in standard library containers or custom data structures, prefix increment (++it) is generally more efficient than postfix increment (it++). The postfix version typically requires creating a temporary copy of the iterator's original state before performing the increment and returning the copy. In contrast, the prefix version increments the iterator directly and returns a reference to the modified iterator, avoiding the overhead of a temporary object.

References:

• Stack Overflow: Is there a performance difference between ++i and i++ in C++?
  https://stackoverflow.com/questions/248549/is-there-a-performance-difference-between-i-and-i-in-c
• GeeksforGeeks: Prefix vs Postfix Increment/Decrement Operators in C++
  https://www.geeksforgeeks.org/prefix-vs-postfix-increment-decrement-operators-in-cpp/
• Fluent C++: The Performance of Prefix vs Postfix Increment Operator
  https://www.fluentcpp.com/2019/02/15/the-performance-of-prefix-vs-postfix-increment-operator/
• Bjarne Stroustrup's FAQ: Why should I prefer prefix to postfix increment?
  https://www.stroustrup.com/bs_faq2.html#iterators
• Modern C++ Best Practices: Prefer prefix increment/decrement
  https://www.modernescpp.com/index.php/prefer-prefix-increment-decrement

Co-Authored-By: Gemini 2.5 Pro (References and desc commit changes)

[am17an]

Have you looked at the #17625?

[GermanAizek]

Have you looked at the #17625?

Oh no, my sorry. Wait, I'll fix it now.

[GermanAizek]

Co-Authored-By: Gemini 2.5 Pro (References and desc commit changes)

@am17an fix it

[CISC]

Cool, all links are dead. :)

Besides I don't believe for a second that there is an actual difference when you compile with optimization.

[GermanAizek]

Cool, all links are dead. :)

I think it's because of the old 2.5 model, although maybe the model was actually trained on links that are no longer relevant.

I thought that at least she would make links and description changes without problems.

[pwilkin]

@CISC I think it's time to unravel the shiny new label.

[am17an]

Let it be known that I had nothing to do with this when the robots come for you