Add limit for unclosed delimiters in lexer diagnostic

[chenyukang]

Fixes #127868

The first commit shows the original diagnostic, and the second commit shows the changes.

[rustbot]

r? @michaelwoerister

rustbot has assigned @michaelwoerister.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[chenyukang]

r? lexer

[nnethercote]

Thanks for splitting this into two commits, it helps with the reviewing :)

r=me once the minor comments above are addressed.

[chenyukang]

@bors r=nnethercote

[bors]

📌 Commit 52bc90c has been approved by nnethercote

It is now in the queue for this repository.

[chenyukang]

@bors r=nnethercote

[bors]

📌 Commit 94a3fd7 has been approved by nnethercote

It is now in the queue for this repository.

[bors]

⌛ Testing commit 94a3fd7 with merge 595316b...

[bors]

☀️ Test successful - checks-actions
Approved by: nnethercote
Pushing 595316b to master...

[rust-timer]

Finished benchmarking commit (595316b): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary -0.2%)

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)	3.9%	[3.9%, 3.9%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-4.3%	[-4.3%, -4.3%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.2%	[-4.3%, 3.9%]	2

Cycles

Results (primary 2.6%, secondary -2.5%)

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)	2.6%	[2.6%, 2.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	2.6%	[2.6%, 2.6%]	1

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 769.935s -> 768.761s (-0.15%)
Artifact size: 331.88 MiB -> 331.87 MiB (-0.00%)