Revert "Auto merge of #135726 - jdonszelmann:attr-parsing, r=oli-obk"

[Kobzol]

Trying to revert #135726 and do some perf. runs on it.

r? @ghost

[Kobzol]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8cbc938 with merge 26f476aea892456bc6d88ffc762d3ff564052d1e...

[bors]

☀️ Try build successful - checks-actions
Build commit: 26f476a (26f476aea892456bc6d88ffc762d3ff564052d1e)

[rust-timer]

Finished benchmarking commit (26f476a): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

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

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.5%	[0.3%, 0.7%]	7
Improvements ✅ (primary)	-0.4%	[-0.8%, -0.2%]	36
Improvements ✅ (secondary)	-0.6%	[-1.3%, -0.3%]	42
All ❌✅ (primary)	-0.4%	[-0.8%, -0.2%]	36

Max RSS (memory usage)

Results (primary 0.3%, secondary 0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.0%	[0.4%, 3.6%]	70
Regressions ❌ (secondary)	1.0%	[0.4%, 3.0%]	60
Improvements ✅ (primary)	-1.0%	[-4.0%, -0.4%]	39
Improvements ✅ (secondary)	-1.0%	[-3.1%, -0.4%]	45
All ❌✅ (primary)	0.3%	[-4.0%, 3.6%]	109

Cycles

Results (primary -0.3%, secondary -0.9%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.4%	[0.4%, 4.6%]	13
Regressions ❌ (secondary)	1.0%	[0.4%, 3.7%]	18
Improvements ✅ (primary)	-0.8%	[-2.9%, -0.4%]	37
Improvements ✅ (secondary)	-1.2%	[-5.2%, -0.4%]	105
All ❌✅ (primary)	-0.3%	[-2.9%, 4.6%]	50

Binary size

Results (primary 0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.1%]	8
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.0%, 0.1%]	8

Bootstrap: 770.608s -> 769.192s (-0.18%)
Artifact size: 361.97 MiB -> 359.64 MiB (-0.64%)

[Kobzol]

I don't think that the PR was the cause, see https://rust-lang.zulipchat.com/#narrow/channel/247081-t-compiler.2Fperformance/topic/Unstable.20cycles.2FRSS/near/501834961.