swift 5.10/nightly: struct 'OpaquePointer' does not conform to the 'Sendable' protocol

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Description

Haven't found whether it was reported or not yet...

OpaquePointer is Sendable by documentation and was Sendable in 5.7/5.8.
But in 5.10/nightly I see the following:

09:35:04 Swift.OpaquePointer:1:23: note: struct 'OpaquePointer' does not conform to the 'Sendable' protocol
09:35:04 @frozen public struct OpaquePointer {

Reproduction

final class Foo: Sendable {
    let v: OpaquePointer
    
    init(v: OpaquePointer) {
        self.v = v
    }
}

Result:

<source>:2:9: warning: stored property 'v' of 'Sendable'-conforming class 'Foo' has non-sendable type 'OpaquePointer'
    let v: OpaquePointer
        ^
Swift.OpaquePointer:1:23: note: struct 'OpaquePointer' does not conform to the 'Sendable' protocol
@frozen public struct OpaquePointer {
                      ^
Compiler returned: 0

Or build https://github.com/swift-server/swift-kafka-client with 5.10/nightly.

Expected behavior

OpaquePointer should be Sendable by documentation, no warning should be emitted.

Environment

swift nightly: https://ci.swiftserver.group/job/swift-kafka-client-swift-nightly-prb/310/console
swift 5.10: https://ci.swiftserver.group/job/swift-kafka-client-swift510-prb/47/console

Additional information

It is a little bit strange that compiler emits this warning as OpaquePointer is struct and should be Sendable by default (according to documentation)

There is additionally
Reproducible example at godbolt

[xedin]

Opaque pointer just like other unsafe pointer types no longer synthesize conformance to Sendable because otherwise they could be used to transfer non-Sendable types across concurrency domains. See https://github.com/apple/swift-evolution/blob/main/proposals/0331-remove-sendable-from-unsafepointer.md for more details.

[blindspotbounty]

Thank you, would be nice to update it in documentation as well