Script to accept Performance comparison request

[robins]

Write a Script that checks for existence of a Script that defines which tests to perform.

/sql/REL9_6_STABLE/a704f8327f56b9a6b38e8d88e465ae021a01bc52.sql

• Branch to perform on
• Commit to perform on (before and after)

[robins]

Have 2 modes

1. If this is an automated request, alert only if diff really high (ideal if it was possible to prove that the diff was consistently high)
2. If this is a manual request (like this Issue is trying to create) then the diff should be posted /alerted irrespective of perf gains.

[robins]

A good example of huge-change / possibly a perf oriented change is this commit.

https://git.postgresql.org/pg/commitdiff/578b229718e8f15fa779e20f086c4b6bb3776106