Revert "linux: try to use libc getrandom to allow interposition"

[jyn514]

This measures the performance impact of #78785 (see #79167 (comment)).

• Revert "Use syscall! for copy_file_range too"
• Revert "Try weak symbols for all linux syscall! wrappers"
• Revert "linux: try to use libc getrandom to allow interposition"

cc @cuviper
r? @ghost

[jyn514]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion

[bors]

⌛ Trying commit 452947c with merge ad6794aa17ebda099a8407e9bd2089ee362fe7fb...

[bors]

☀️ Try build successful - checks-actions
Build commit: ad6794aa17ebda099a8407e9bd2089ee362fe7fb (ad6794aa17ebda099a8407e9bd2089ee362fe7fb)

[rust-timer]

Queued ad6794aa17ebda099a8407e9bd2089ee362fe7fb with parent 7445993, future comparison URL.

[rust-timer]

Finished benchmarking try commit (ad6794aa17ebda099a8407e9bd2089ee362fe7fb): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot modify labels: +S-waiting-on-review -S-waiting-on-perf