chore(asm): use byte pointer instead of c_char_p (#10428)

[christophe-papazian]

Backport of #10428

(cherry picked from commit 46bb2a8)

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance
  policy

[datadog-dd-trace-py-rkomorn]

Datadog Report

Branch report: backport-10428-to-2.9
Commit report: 7fa8928
Test service: dd-trace-py

✅ 0 Failed, 110492 Passed, 2895 Skipped, 49m 52.01s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-08-29 10:01:00

Comparing candidate commit 7fa8928 in PR branch backport-10428-to-2.9 with baseline commit 151b7d7 in branch 2.9.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 209 metrics, 9 unstable metrics.