Rollup merge of #43157 - zackmdavis:mail_map, r=steveklabnik

Rollup merge of #43157 - zackmdavis:mail_map, r=steveklabnik

update .mailmap

It's nice to have an up-to-date .mailmap so that contributor listings (like those provided by `git shortlog` or http://thanks.rust-lang.org/) don't split the same author's contributions across two or more variations of their name.

Affected contributors—

@Aaronepower (3 commits as "Aaron Power", 1 as "Aaronepower")
@djrollins (5 commits as "Daniel J Rollins", 1 as "Daniel Rollins")
@eddyb (345 commits as "Eduard-Mihai Burtescu", 678 as "Eduard Burtescu", assuming former is canonical based on recency and GitHub profile display name)
@edunham (1 more recent commit contradicts existing .mailmap entry)
@GuillaumeGomez (942 commits as "Guillaume Gomez", 55 commits as "ggomez", 22 commits as "GuillaumeGomez")
@jonathandturner (362 commits as "Jonathan Turner", 1 as "jonathandturner")
@Mark-Simulacrum (248 commits as "Mark Simulacrum", 97 "Mark-Simulacrum")
@fiveop (1 commit each as "Philipp Matthias Schäfer" and "Philipp Matthias Schaefer", assuming former is canonical based on GitHub profile display name)
@shyaamsundhar (1 commit as "Shyam Sundar B", 3 as ShyamSundarB, assuming former is canonical based on recency)
@steveklabnik (1634 commits as "Steve Klabnik", 41 as "steveklabnik")