swift

f988acc7 - [cherry-pick release/6.0][Shims] Don't redeclare lgamma_r in macOS 15.0 and associated SDKs

[cherry-pick release/6.0][Shims] Don't redeclare lgamma_r in macOS 15.0 and associated SDKs macOS 15.0, iOS 18.0, et al has started unconditionally declaring `lgamma_r` in <math.h>, add a __has_include in SwiftShims to detect that and not redeclare it when building against those SDK versions. rdar://115192929