update isolate_highest_one for NonZero<T>

## Rationale
Let `x = self` and
`m = (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()))`
Then the previous code computed `NonZero::new_unchecked(x & m)`.
Since `m` has exactly one bit set (the most significant 1-bit of `x`), `(x & m) == m`.
Therefore, the masking step was redundant.

The shift is safe and does not need wrapping because:
* `self.leading_zeros() < $Int::BITS` because `self` is non-zero.
* The result of `unchecked_shr` is non-zero, satisfying the `NonZero` invariant. if wrapping happens we would be violating `NonZero` invariants.

why this micro optimization?
the old code was suboptimal it duplicated `$Int`’s isolate_highest_one logic instead of delegating to it. Since the type already wraps `$Int`, either delegation should be used for clarity or, if keeping a custom implementation, it should be optimized as above.

Rollup of 15 pull requests

Successful merges:

 - #147404 (Fix issue with callsite inline attribute not being applied sometimes.)
 - #147534 (Implement SIMD funnel shifts in const-eval/Miri)
 - #147686 (update isolate_highest_one for NonZero<T>)
 - #148020 (Show backtrace on allocation failures when possible)
 - #148204 (Modify contributor email entries in .mailmap)
 - #148230 (rustdoc: Properly highlight shebang, frontmatter & weak keywords in source code pages and code blocks)
 - #148555 (Fix rust-by-example spanish translation)
 - #148556 (Fix suggestion for returning async closures)
 - #148585 ([rustdoc] Replace `print` methods with functions to improve code readability)
 - #148600 (re-use `self.get_all_attrs` result for pass indirectly attribute)
 - #148612 (Add note for identifier with attempted hygiene violation)
 - #148613 (Switch hexagon targets to rust-lld)
 - #148644 ([bootstrap] Make `--open` option work with `doc src/tools/error_index_generator`)
 - #148649 (don't completely reset `HeadUsages`)
 - #148675 (Remove eslint-js from npm dependencies)

r? `@ghost`
`@rustbot` modify labels: rollup

update isolate_highest_one for NonZero<T>

## Rationale
Let `x = self` and
`m = (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()))`
Then the previous code computed `NonZero::new_unchecked(x & m)`.
Since `m` has exactly one bit set (the most significant 1-bit of `x`), `(x & m) == m`.
Therefore, the masking step was redundant.

The shift is safe and does not need wrapping because:
* `self.leading_zeros() < $Int::BITS` because `self` is non-zero.
* The result of `unchecked_shr` is non-zero, satisfying the `NonZero` invariant. if wrapping happens we would be violating `NonZero` invariants.

why this micro optimization?
the old code was suboptimal it duplicated `$Int`’s isolate_highest_one logic instead of delegating to it. Since the type already wraps `$Int`, either delegation should be used for clarity or, if keeping a custom implementation, it should be optimized as above.

Rollup of 16 pull requests

Successful merges:

 - #147534 (Implement SIMD funnel shifts in const-eval/Miri)
 - #147686 (update isolate_highest_one for NonZero<T>)
 - #148020 (Show backtrace on allocation failures when possible)
 - #148204 (Modify contributor email entries in .mailmap)
 - #148230 (rustdoc: Properly highlight shebang, frontmatter & weak keywords in source code pages and code blocks)
 - #148279 (rustc_builtin_macros: rename bench parameter to avoid collisions with user-defined function names)
 - #148555 (Fix rust-by-example spanish translation)
 - #148556 (Fix suggestion for returning async closures)
 - #148585 ([rustdoc] Replace `print` methods with functions to improve code readability)
 - #148600 (re-use `self.get_all_attrs` result for pass indirectly attribute)
 - #148612 (Add note for identifier with attempted hygiene violation)
 - #148613 (Switch hexagon targets to rust-lld)
 - #148619 (Enable std locking functions on AIX)
 - #148644 ([bootstrap] Make `--open` option work with `doc src/tools/error_index_generator`)
 - #148649 (don't completely reset `HeadUsages`)
 - #148675 (Remove eslint-js from npm dependencies)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 10 pull requests

Successful merges:

 - #145656 (Stabilize s390x `vector` target feature and `is_s390x_feature_detected!` macro)
 - #147024 (std_detect: Support run-time detection on OpenBSD using elf_aux_info)
 - #147534 (Implement SIMD funnel shifts in const-eval/Miri)
 - #147540 (Stabilise `as_array` in `[_]` and `*const [_]`; stabilise `as_mut_array` in `[_]` and `*mut [_]`.)
 - #147686 (update isolate_highest_one for NonZero<T>)
 - #148230 (rustdoc: Properly highlight shebang, frontmatter & weak keywords in source code pages and code blocks)
 - #148555 (Fix rust-by-example spanish translation)
 - #148556 (Fix suggestion for returning async closures)
 - #148585 ([rustdoc] Replace `print` methods with functions to improve code readability)
 - #148600 (re-use `self.get_all_attrs` result for pass indirectly attribute)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 10 pull requests

Successful merges:

 - #145656 (Stabilize s390x `vector` target feature and `is_s390x_feature_detected!` macro)
 - #147024 (std_detect: Support run-time detection on OpenBSD using elf_aux_info)
 - #147534 (Implement SIMD funnel shifts in const-eval/Miri)
 - #147540 (Stabilise `as_array` in `[_]` and `*const [_]`; stabilise `as_mut_array` in `[_]` and `*mut [_]`.)
 - #147686 (update isolate_highest_one for NonZero<T>)
 - #148230 (rustdoc: Properly highlight shebang, frontmatter & weak keywords in source code pages and code blocks)
 - #148555 (Fix rust-by-example spanish translation)
 - #148556 (Fix suggestion for returning async closures)
 - #148585 ([rustdoc] Replace `print` methods with functions to improve code readability)
 - #148600 (re-use `self.get_all_attrs` result for pass indirectly attribute)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 10 pull requests

Successful merges:

 - #145656 (Stabilize s390x `vector` target feature and `is_s390x_feature_detected!` macro)
 - #147024 (std_detect: Support run-time detection on OpenBSD using elf_aux_info)
 - #147534 (Implement SIMD funnel shifts in const-eval/Miri)
 - #147540 (Stabilise `as_array` in `[_]` and `*const [_]`; stabilise `as_mut_array` in `[_]` and `*mut [_]`.)
 - #147686 (update isolate_highest_one for NonZero<T>)
 - #148230 (rustdoc: Properly highlight shebang, frontmatter & weak keywords in source code pages and code blocks)
 - #148555 (Fix rust-by-example spanish translation)
 - #148556 (Fix suggestion for returning async closures)
 - #148585 ([rustdoc] Replace `print` methods with functions to improve code readability)
 - #148600 (re-use `self.get_all_attrs` result for pass indirectly attribute)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of #147686 - vrtgs:non-zero-isolate, r=joboet

update isolate_highest_one for NonZero<T>

## Rationale
Let `x = self` and
`m = (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()))`
Then the previous code computed `NonZero::new_unchecked(x & m)`.
Since `m` has exactly one bit set (the most significant 1-bit of `x`), `(x & m) == m`.
Therefore, the masking step was redundant.

The shift is safe and does not need wrapping because:
* `self.leading_zeros() < $Int::BITS` because `self` is non-zero.
* The result of `unchecked_shr` is non-zero, satisfying the `NonZero` invariant. if wrapping happens we would be violating `NonZero` invariants.

why this micro optimization?
the old code was suboptimal it duplicated `$Int`’s isolate_highest_one logic instead of delegating to it. Since the type already wraps `$Int`, either delegation should be used for clarity or, if keeping a custom implementation, it should be optimized as above.

update isolate_highest_one for NonZero<T>

## Rationale
Let `x = self` and
`m = (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()))`
Then the previous code computed `NonZero::new_unchecked(x & m)`.
Since `m` has exactly one bit set (the most significant 1-bit of `x`), `(x & m) == m`.
Therefore, the masking step was redundant.

The shift is safe and does not need wrapping because:
* `self.leading_zeros() < $Int::BITS` because `self` is non-zero.
* The result of `unchecked_shr` is non-zero, satisfying the `NonZero` invariant. if wrapping happens we would be violating `NonZero` invariants.

why this micro optimization?
the old code was suboptimal it duplicated `$Int`’s isolate_highest_one logic instead of delegating to it. Since the type already wraps `$Int`, either delegation should be used for clarity or, if keeping a custom implementation, it should be optimized as above.