Only keep one dep-graph in memory

[cjgillot]

This is a re-implementation from scratch of the dep-graph storage.

Instead of keeping the deserialized dep-graph immutable in memory,
this implementation modifies it in-place, and appends new dep-nodes to it.

The graph is cleaned-up at saving time, where all the nodes are renumbered to remove stale nodes.

r? @ghost

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 16d80aed4c981fa64a23bdd86665e6d424d00e31 with merge 3e82a8e64b10e2ad24021e1bd97e5374fbfa9757...

[bors]

☔ The latest upstream changes (presumably #70951) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☀️ Try build successful - checks-actions
Build commit: 3e82a8e64b10e2ad24021e1bd97e5374fbfa9757 (3e82a8e64b10e2ad24021e1bd97e5374fbfa9757)

[rust-timer]

Queued 3e82a8e64b10e2ad24021e1bd97e5374fbfa9757 with parent e7c23ab, future comparison URL.

[rust-timer]

Finished benchmarking try commit (3e82a8e64b10e2ad24021e1bd97e5374fbfa9757): 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

[bjorn3]

Significant regressions of up to 6%.

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 10844018aa5118c4407b8c512ac2c55e03ea0a47 with merge 7d3e46cdccabc8f3cfc056edc05a570756da768c...

[bors]

☀️ Try build successful - checks-actions
Build commit: 7d3e46cdccabc8f3cfc056edc05a570756da768c (7d3e46cdccabc8f3cfc056edc05a570756da768c)

[rust-timer]

Queued 7d3e46cdccabc8f3cfc056edc05a570756da768c with parent a15f484, future comparison URL.

[rust-timer]

Finished benchmarking try commit (7d3e46cdccabc8f3cfc056edc05a570756da768c): 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 try @rust-timer queue

[cjgillot]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 91734f1 with merge de903c91da2158c76094697c62f036b7a3324155...

[bors]

💔 Test failed - checks-actions

[cjgillot]

With atomics
@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

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

[bors]

⌛ Trying commit 0c7de43 with merge cfb73662247a17bcf07f635d74389d1aeb2df26c...

[bors]

☀️ Try build successful - checks-actions
Build commit: cfb73662247a17bcf07f635d74389d1aeb2df26c (cfb73662247a17bcf07f635d74389d1aeb2df26c)

[rust-timer]

Queued cfb73662247a17bcf07f635d74389d1aeb2df26c with parent b36f770, future comparison URL.

[rust-timer]

Finished benchmarking try commit (cfb73662247a17bcf07f635d74389d1aeb2df26c): 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]

Closed in favour of #82780.