Suggestion: Make BytesMut::resize inline.

[Sol-Ell]

Problem

The current implementation of BytesMut::resize is not inlined, which may lead to unnecessary function calls.

[Current implementation](

bytes/src/bytes_mut.rs

Lines 479 to 500 in e0f3a25

	pub fn resize(&mut self, new_len: usize, value: u8) {
	let additional = if let Some(additional) = new_len.checked_sub(self.len()) {
	additional
	} else {
	self.truncate(new_len);
	return;
	};
	if additional == 0 {
	return;
	}
	self.reserve(additional);
	let dst = self.spare_capacity_mut().as_mut_ptr();
	// SAFETY: `spare_capacity_mut` returns a valid, properly aligned pointer and we've
	// reserved enough space to write `additional` bytes.
	unsafe { ptr::write_bytes(dst, value, additional) };
	// SAFETY: There are at least `new_len` initialized bytes in the buffer so no
	// uninitialized bytes are being exposed.
	unsafe { self.set_len(new_len) };
	}

)

Proposed Solution

Partially inline BytesMut::resize to reduce function call overhead and improve performance.

[Updated implementation](https://github.com/Sol-Ell/bytes/blob/ed9989b499cf390340cf255548d7a898aea29ad3/src/bytes_mut.rs#L479-L500)