[SPARK-31187][SQL] Sort the whole-stage codegen debug output by codegenStageId

[rednaxelafx]

What changes were proposed in this pull request?

Spark SQL's whole-stage codegen (WSCG) supports dumping the generated code to help with debugging. One way to get the generated code is through df.queryExecution.debug.codegen, or SQL EXPLAIN CODEGEN statement.

The generated code is currently printed without specific ordering, which can make debugging a bit annoying. This PR makes a minor improvement to sort the codegen dump by the codegenStageId, ascending.

After this change, the following query:

spark.range(10).agg(sum('id)).queryExecution.debug.codegen

will always dump the generated code in a natural, stable order. A version of this example with shorter output is:

spark.range(10).agg(sum('id)).queryExecution.debug.codegenToSeq.map(_._1).foreach(println)
*(1) HashAggregate(keys=[], functions=[partial_sum(id#8L)], output=[sum#15L])
+- *(1) Range (0, 10, step=1, splits=16)

*(2) HashAggregate(keys=[], functions=[sum(id#8L)], output=[sum(id)#12L])
+- Exchange SinglePartition, true, [id=#30]
   +- *(1) HashAggregate(keys=[], functions=[partial_sum(id#8L)], output=[sum#15L])
      +- *(1) Range (0, 10, step=1, splits=16)

The number of codegen stages within a single SQL query tends to be very small, most likely < 50, so the overhead of adding the sorting shouldn't be significant.

Why are the changes needed?

Minor improvement to aid WSCG debugging.

Does this PR introduce any user-facing change?

No user-facing change for end-users; minor change for developers who debug WSCG generated code.

How was this patch tested?

Manually tested the output; all other tests still pass.

[gengliangwang]

LGTM

[SparkQA]

Test build #120026 has finished for PR 27955 at commit c64b778.

• This patch fails due to an unknown error code, -9.
• This patch merges cleanly.
• This patch adds no public classes.

[kiszk]

retest this please

[SparkQA]

Test build #120029 has finished for PR 27955 at commit c64b778.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[maropu]

Thanks! Merged to master/3.0.

[maropu]

Since I think this PR improves debugability, I merged this into 3.0, too.