Reintroduce support for CLI option to disable blocking kernel

[oleksandr-pavlyk]

This PR reintroduced --disable-blocking-kernel CLI option at downstream user's request.

I was removed in #254, to disallow specifying once existing --run-once option without using --disable-blocking-kernel.

Closes #425

[oleksandr-pavlyk]

@mfranzrebsal for viz.

[oleksandr-pavlyk]

@coderabbitai full review

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 84ce36c and 7baa3fc.

📒 Files selected for processing (5)

• docs/cli_help.md
• nvbench/blocking_kernel.cu
• nvbench/option_parser.cu
• nvbench/option_parser.cuh
• testing/option_parser.cu

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📝 Walkthrough

Summary by CodeRabbit

• New Features
  • Added the --disable-blocking-kernel command-line option to disable blocking-kernel timing for cold measurements while keeping repeated benchmark runs intact.
  • The setting applies to the most recent selected benchmark, or globally for benchmarks specified after the flag.
  • Updated deadlock/profiling guidance to reflect the correct combination of options for repeated execution.
• Documentation
  • Added CLI help documentation for --disable-blocking-kernel.
• Tests
  • Added coverage verifying option parsing, ordering behavior, and interaction with --profile.

Walkthrough

Changes

Blocking-kernel CLI support

Layer / File(s)	Summary
Parse and apply the option nvbench/option_parser.cuh, nvbench/option_parser.cu	The parser recognizes --disable-blocking-kernel, stores it for future benchmarks when none is selected, or applies it to the latest benchmark.
Validate and document behavior testing/option_parser.cu, docs/cli_help.md, nvbench/blocking_kernel.cu	Tests cover option ordering and profile interactions; help and deadlock diagnostics describe the option’s behavior.

Assessment against linked issues

Objective	Addressed	Explanation
Restore CLI support for independently disabling the blocking kernel [#425]	✅

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