[swift-dev] Why are we re-linking?

[Chris Lattner]

> On Apr 6, 2016, at 11:08 AM, Jordan Rose via swift-dev <swift-dev at swift.org> wrote:
> 
> I imagine it's because your git hash has changed, which is used in the --version output for swiftc. I'm not sure how to avoid that cost entirely, but we could add a CMake option to not do it (which you could set locally), and we could probably move it to a library that isn't used by most of those tools (so that we're only re-linking swiftc).

Could we move the hash to be a text file stored next to the executables in the installdir?  That way the text file gets updated, but not the binaries?

-Chris