Parse `replacement` parameter of `__attribute__((deprecated(...))`

[friedbunny]

#843 covered parsing the message parameter of the deprecated __attribute__, but clang/Xcode also support a second argument named replacement, which takes a method/property signature and prompts the developer via fix-it in Xcode.

If there’s sourcekit(ten) support for replacement, it would be ideal to include the specified replacement and linkify it.

Example usage:

@property SomeClass someProperty __attribute__((deprecated("Whatever this property did is no longer supported.", "someImprovedProperty")));

Would result in jazzy output similar to:

[johnfairh]

libclang doesn't expose the 'replacement' part at all so this is trickier than the rest of deprecated support was.

[chwastek]

I'm not sure... does it work after all or not?

[johnfairh]

No, there've been no sourcekitten/jazzy changes made for this.