This implements the protocols and static functions proposed in SE-0246, plus some initial test coverage. It also has some rough accompanying cleanup of tgmath. It does not include the globals (on scalars or SIMD types) nor does it deprecate much in tgmath.h.
The `ObjectIdentifier(object as AnyObject)` is not necessarily stable; this breaks reflexivity for ==, and it makes the hash encoding nondeterministic.
The new definition diverges from the existing hashValue: it feeds all path components to the hasher, rather than just a limited subset.
Hashing all the bits that are compared in == is necessary to ensure proper operation of the hash table.
* Revert "Merge pull request #23791 from compnerd/you-know-nothing-clang"
This reverts commit 5150981150, reversing
changes made to 8fc305c03e.
* Revert "Merge pull request #23780 from compnerd/math-is-terrible"
This reverts commit 2d7fedd25f, reversing
changes made to 0205150b8f.
* Revert "Merge pull request #23140 from stephentyrone/mafs"
This reverts commit 777750dc51, reversing
changes made to 0c8920e747.
The initializer was originally introduced without proper availability; in https://github.com/apple/swift/pull/23643, we fixed this by applying the `@_alwaysEmitIntoClient` attribute. However, this had the unfortunate side-effect that the symbol disappeared from `libswiftCore.dylib`, which somehow confuses some simulator builds.
Try to figure out what’s happening by replacing the third closure argument with an integer return value. This changes the mangled name of the bulk initializer, which should make it more obvious how/why these builds fail.
rdar://problem/49479386
This commit implements SE-0246, by adding conformance to Real to the Float, CGFloat, Double, and Float80 types, implemented either in terms of the system's C math library, existing standard library functionality, or LLVM intrinsics. It includes basic test coverage for these new functions, and deprecates and obsoletes *some* existing functionality in the Platform overlay. We still need to make a decision about how to handle the remaining "tgmath" functions, because obsoleting them is technically a source-breaking change (if users have unqualified names like "exp(1)", it's fine, but it would break users who have used qualified names like "Darwin.exp(1)".)
