Rollup merge of #5410 - dtolnay:trivially, r=flip1995

Downgrade trivially_copy_pass_by_ref to pedantic

The rationale for this lint is documented as:

> In many calling conventions instances of structs will be passed through registers if they fit into two or less general purpose registers.

I think the purported performance benefits of clippy's recommendation are overstated. This isn't worth asking people to sprinkle code with more `*`​`*`​`&`​`*`​`&` to chase the alleged performance.

This should be a pedantic lint that is disabled by default and opted in if some specific performance sensitive codebase determines that it is worthwhile.

As a reminder, a typical place that a reference to a primitive would come up is if the function is used as a filter. Triggering a performance-oriented lint on this type of code is the definition of pedantic.

```rust
fn filter(_n: &i32) -> bool {
    true
}

fn main() {
    let v = vec![1, 2, 3];
    v.iter().copied().filter(filter).for_each(drop);
}
```

```console
warning: this argument (4 byte) is passed by reference, but would be more efficient if passed by value (limit: 8 byte)
 --> src/main.rs:1:15
  |
1 | fn filter(_n: &i32) -> bool {
  |               ^^^^ help: consider passing by value instead: `i32`
```

changelog: Remove trivially_copy_pass_by_ref from default set of enabled lints

0 files changed, 0 insertions, 0 deletions