pkg/col/colserde: potential performance regression

pkg/col/colserde [performance regression](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachprodMicrobenchmarkWeeklyWip/20911487?buildTab=log) on master @ [2b0948f73804d08c7e0fe12a5151b54770831c8f](https://github.com/cockroachdb/cockroach/commits/2b0948f73804d08c7e0fe12a5151b54770831c8f):

Performance regressions detected in package pkg/col

Comparison: v25.4.2 (2c80e22e) -> refs/heads/master (2b0948f7)

Found 14 benchmark(s) with regressions ≥20%:

- [pkg/col/colserde→Conversion/bytes/nullFraction=0.00/Deserialize-32 (sec/op): +74.57% (74.6%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.00/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.50/Deserialize-32 (sec/op): +74.25% (74.3%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.50/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.25/Deserialize-32 (sec/op): +74.05% (74.0%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.25/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.00/Deserialize-32 (sec/op): +55.70% (55.7%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.00/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.50/Deserialize-32 (sec/op): +55.44% (55.4%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.50/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.25/Deserialize-32 (sec/op): +54.80% (54.8%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.25/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.00/Deserialize-32 (B/s): -42.72% (42.7%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.00/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.50/Deserialize-32 (B/s): -42.61% (42.6%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.50/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.25/Deserialize-32 (B/s): -42.54% (42.5%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.25/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.00/Deserialize-32 (B/s): -35.78% (35.8%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.00/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.50/Deserialize-32 (B/s): -35.69% (35.7%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.50/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes_inlined/nullFraction=0.25/Deserialize-32 (B/s): -35.39% (35.4%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes_inlined/nullFraction=0.25/Deserialize-32&package=pkg/col/colserde)
- [pkg/col/colserde→Conversion/bytes/nullFraction=0.00/Serialize-32 (B/op): +100.00% (100.0%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Conversion/bytes/nullFraction=0.00/Serialize-32&package=pkg/col/colserde)
- [pkg/col/coldata→Append/bytes/AppendNoInline/NullProbability=0.0-32 (B/op): +27.53% (27.5%)](https://microbench.testeng.crdb.io/dashboard/?benchmark=Append/bytes/AppendNoInline/NullProbability=0.0-32&package=pkg/col/coldata)
Help

See also: [How To Investigate a Go Test Failure \(internal\)](https://cockroachlabs.atlassian.net/l/c/HgfXfJgM)

Jira issue: CRDB-58256