Revert "Math functions for Swift"

[xedin]

Reverts #23140

Just the test to see if this is really what introduced source compatibility regressions:

https://ci.swift.org/view/Source%20Compatibility/job/swift-master-source-compat-suite/3384/console

[xedin]

@swift-ci please test source compatibility

[xedin]

Currently failing:

02:04:20   FAIL: IBAnimatable, 4.0, eb4acb, IBAnimatableApp, generic/platform=iOS
02:04:20   FAIL: IBAnimatable, 4.0, eb4acb, IBAnimatable, generic/platform=iOS
02:04:20   FAIL: Surge, 5.0, 38a328, Surge-watchOS, generic/platform=watchOS
02:04:20   FAIL: Surge, 5.0, 38a328, Surge-tvOS, generic/platform=tvOS
02:04:20   FAIL: Surge, 5.0, 38a328, Surge-macOS, generic/platform=macOS
02:04:20   FAIL: Surge, 5.0, 38a328, Surge-iOS, generic/platform=iOS
02:04:20   FAIL: Surge, 4.2, 38a328, Surge-watchOS, generic/platform=watchOS
02:04:20   FAIL: Surge, 4.2, 38a328, Surge-tvOS, generic/platform=tvOS
02:04:20   FAIL: Surge, 4.2, 38a328, Surge-macOS, generic/platform=macOS
02:04:20   FAIL: Surge, 4.2, 38a328, Surge-iOS, generic/platform=iOS
02:04:20   FAIL: SwifterSwift, 4.0, d3c3fd, SwifterSwift-watchOS, generic/platform=watchOS
02:04:20   FAIL: SwifterSwift, 4.0, d3c3fd, SwifterSwift-tvOS, generic/platform=tvOS
02:04:20   FAIL: SwifterSwift, 4.0, d3c3fd, SwifterSwift-macOS, generic/platform=macOS
02:04:20   FAIL: SwifterSwift, 4.0, d3c3fd, SwifterSwift-iOS, generic/platform=iOS

[xedin]

@stephentyrone @airspeedswift Math functions PR introducted multiple source compatibility regressions in external and internal projects

[tkremenek]

Let's get the change reverted until we can resolve the source compatibility breaks before we land. All API changes to the Standard Library should go through the compatibility suite before merging.

[xedin]

Looks like this is going to be a non-trivial revert because there are conflicts already. @stephentyrone would be the best person to do that.

[stephentyrone]

@xedin #23800

[xedin]

@stephentyrone thank you!