Revert "Change prefetch to avoid deadlock"

[Zoxc]

This reverts #118488 as that is just a workaround.

Blocked on rust-lang/rustc-rayon#12 to avoid deadlocks.

[rustbot]

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[bors]

☔ The latest upstream changes (presumably #137535) made this pull request unmergeable. Please resolve the merge conflicts.

[apiraino]

@Zoxc I assume the S-blocked label can be now lifted, correct?

You and cc: @matthiaskrgr probably know why it was applied.

@rustbot label -S-blocked

[matthiaskrgr]

I added the label because of "Blocked on rust-lang/rustc-rayon#12 to avoid deadlocks."

looks like the upstream pr has not been merged to this day

[Zoxc]

Yeah, it can be unblocked since #143035 landed.

It does regress performance now, so I'll have to do some profiling to see if that can be fixed.

Benchmark	Before	After		Before	After		Before	After
	Time	Time	%	Physical Memory	Physical Memory	%	Committed Memory	Committed Memory	%
🟣 clap:check	0.4302s	0.4326s	0.56%	202.12 MiB	202.34 MiB	0.11%	282.69 MiB	283.03 MiB	0.12%
🟣 hyper:check	0.1157s	0.1174s	💔 1.48%	129.28 MiB	129.19 MiB	-0.06%	209.59 MiB	209.58 MiB	-0.01%
🟣 regex:check	0.2558s	0.2591s	💔 1.29%	162.13 MiB	162.35 MiB	0.13%	237.77 MiB	238.03 MiB	0.11%
🟣 syn:check	0.4937s	0.4960s	0.46%	196.09 MiB	196.26 MiB	0.08%	272.40 MiB	272.54 MiB	0.05%
Total	1.2954s	1.3051s	0.75%	689.62 MiB	690.14 MiB	0.07%	1002.45 MiB	1003.17 MiB	0.07%
Summary	1.0000s	1.0095s	0.95%	1 byte	1.00 bytes	0.07%	1 byte	1.00 bytes	0.07%