Avoid generating QueryMap::extend for each key type

[Mark-Simulacrum]

Should be a small win on compile times for rustc_query_impl, where this ends up getting codegen'd.

[rust-highfive]

r? @estebank

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[Mark-Simulacrum]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit 61fd56f with merge b4044d2852213f861e5f50ff61ed350034e92f09...

[bors]

☀️ Try build successful - checks-actions
Build commit: b4044d2852213f861e5f50ff61ed350034e92f09 (b4044d2852213f861e5f50ff61ed350034e92f09)

[rust-timer]

Queued b4044d2852213f861e5f50ff61ed350034e92f09 with parent 4de7572, future comparison URL.

[rust-timer]

Finished benchmarking try commit (b4044d2852213f861e5f50ff61ed350034e92f09): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[cjgillot]

@bors r+

[bors]

📌 Commit 61fd56f has been approved by cjgillot

[bors]

⌛ Testing commit 61fd56f with merge 3a1cd0e...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 3a1cd0e to master...