Refactor some char, u8 ASCII functions to be branchless

[okaneco]

Extract conditions in singular matches! with or-patterns to individual matches! statements which enables branchless code output. The following functions were changed:

• is_ascii_alphanumeric
• is_ascii_hexdigit
• is_ascii_punctuation

Added codegen tests

---

Continued from #103024.
Based on the comment from @scottmcm #103024 (review).

The unmodified is_ascii_* functions didn't seem to benefit from extracting the conditions.

I've never written a codegen test before, but I tried to check that no branches were emitted.

[rustbot]

r? @thomcc

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[thomcc]

Assuming CI comes back green this seems fine to me. Thanks.

@bors r+ rollup=never

[bors]

📌 Commit 465ffc9 has been approved by thomcc

It is now in the queue for this repository.

[bors]

⌛ Testing commit 465ffc9 with merge 707d8c3...

[bors]

☀️ Test successful - checks-actions
Approved by: thomcc
Pushing 707d8c3 to master...

[rust-timer]

Finished benchmarking commit (707d8c3): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.6%	[-0.6%, -0.6%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.6%	[-0.6%, -0.6%]	1

Max RSS (memory usage)

Results

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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.7%	[-2.7%, -2.7%]	1
All ❌✅ (primary)	-	-	0

Cycles

Results

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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-9.3%	[-9.3%, -9.3%]	2
All ❌✅ (primary)	-	-	0

Binary size

Results

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)	0.0%	[0.0%, 0.0%]	4
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.1%, -0.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.0%	[-0.1%, 0.0%]	5

Bootstrap: 635.259s -> 634.528s (-0.12%)
Artifact size: 304.44 MiB -> 304.48 MiB (0.01%)

[SUPERCILEX]

For those seeing this PR in twir and wondering why the compiler isn't already doing this, the key difference is that match assumes a logical OR rather than a binary OR:

pub fn f(x: char) -> bool {matches!(x, '0'..='9') | matches!(x, 'A'..='Z') | matches!(x, 'a'..='z')}
pub fn f2(x: char) -> bool {matches!(x, '0'..='9') || matches!(x, 'A'..='Z') || matches!(x, 'a'..='z')}
pub fn f3(x: char) -> bool {matches!(x, '0'..='9' | 'A'..='Z' | 'a'..='z')}