[cxx-interop] import static operator call from C++23 as member callAs…

[hyp]

…Function functions in Swift to preserve source compatibility

[hyp]

This is needed to build String.swift in stdlib's CxxStdlib module after MSVC 17.10 update: microsoft/STL@2fa1641#diff-6692e0333a1981f812fabb0a95f0f66c016830e2a7f3f393c990795a8c2d26da , fixes:

S:/SourceCache/swift/stdlib/public/Cxx/std/String.swift:164:49: error: value of type '__swift_interopHashOfString' (aka 'std.hash<basic_string<CChar, char_traits<CChar>, allocator<CChar>>>') has no member 'callAsFunction'
162 |   public func hash(into hasher: inout Hasher) {
163 |     // Call std::hash<std::string>::operator()
164 |     let cxxHash = __swift_interopHashOfString().callAsFunction(self)
    |                                                 `- error: value of type '__swift_interopHashOfString' (aka 'std.hash<basic_string<CChar, char_traits<CChar>, allocator<CChar>>>') has no member 'callAsFunction'
165 |     hasher.combine(cxxHash)
166 |   }

[hyp]

@swift-ci please smoke test

[hyp]

@swift-ci please test

[egorzhdan]

Thanks! I have a couple comments about tests.

[hyp]

@swift-ci please test

[hyp]

@swift-ci please test source compatibility

[egorzhdan]

LGTM except for the failing tests, thanks!

[hyp]

@swift-ci please test

[egorzhdan]

Looks like this is failing with an assertion in rebranch:

Assertion failed: (isInstance() && "No 'this' for static methods!"), function getThisType, file DeclCXX.cpp, line 2598.

https://ci.swift.org/view/Swift%20rebranch/job/oss-swift-rebranch-incremental-RA-macos/4764/

[egorzhdan]

Here's a PR with the fix for rebranch: #75907