refactor(ast): shorten serialize code using let chains

[overlookmotel]

Refactor. Shorten some ESTree serialization code by using let chains.

It may also be marginally faster, due to only fetching start in one place (first_stmt.span() should be branchless and just a couple of ops, as every struct has span field in same position).

[overlookmotel]

• refactor(ast): shorten serialize code using let chains #13100 👈 (View in Graphite)
• main

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[Copilot]

Pull Request Overview

This PR refactors the get_ts_start_span function in the AST serialization module to use Rust's let chains syntax for more concise code. The functionality remains identical while reducing code duplication.

Key changes:

• Simplified nested if-let patterns using let chains
• Eliminated duplicate variable assignments and return statements
• Restructured control flow to use a single return point

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13100 will not alter performance

_{Comparing 08-14-refactor_ast_shorten_serialize_code_using_let_chains (7b86340) with main (3048302)}

Summary

✅ 34 untouched benchmarks

[overlookmotel]

Small change, and I think I know the serialization code better than anyone, so merging without review.

[overlookmotel]

Merge activity

• Aug 14, 9:00 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Aug 14, 9:00 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
• Aug 14, 9:10 PM UTC: Merged by the Graphite merge queue.