[stdlib] Move unused functions to LegacyABI.swift (#75462)

Author: benrimmington

stdlib/public/core/IntegerTypes.swift.gyb

@@ -761,26 +761,6 @@ extension Int {
   }
 }
 
-@_transparent
-@inlinable
-internal func _unsafePlus(_ lhs: Int, _ rhs: Int) -> Int {
-#if INTERNAL_CHECKS_ENABLED
-  return lhs + rhs
-#else
-  return lhs &+ rhs
-#endif
-}
-
-@_transparent
-@inlinable
-internal func _unsafeMinus(_ lhs: Int, _ rhs: Int) -> Int {
-#if INTERNAL_CHECKS_ENABLED
-  return lhs - rhs
-#else
-  return lhs &- rhs
-#endif
-}
-
 @_unavailableInEmbedded
 internal struct _IntegerAnyHashableBox<
   Base: FixedWidthInteger

stdlib/public/core/LegacyABI.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -87,3 +87,29 @@ extension String.UTF16View {
   @inlinable @inline(__always)
   internal var _shortHeuristic: Int { return 32 }
 }
+
+@usableFromInline
+internal func unimplemented_utf8_32bit(
+  _ message: String = "",
+  file: StaticString = #file, line: UInt = #line
+) -> Never {
+  fatalError("32-bit: Unimplemented for UTF-8 support", file: file, line: line)
+}
+
+@usableFromInline
+internal func _unsafePlus(_ lhs: Int, _ rhs: Int) -> Int {
+#if INTERNAL_CHECKS_ENABLED
+  return lhs + rhs
+#else
+  return lhs &+ rhs
+#endif
+}
+
+@usableFromInline
+internal func _unsafeMinus(_ lhs: Int, _ rhs: Int) -> Int {
+#if INTERNAL_CHECKS_ENABLED
+  return lhs - rhs
+#else
+  return lhs &- rhs
+#endif
+}

stdlib/public/core/String.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -12,14 +12,6 @@
 
 import SwiftShims
 
-@inlinable @_transparent
-internal func unimplemented_utf8_32bit(
-  _ message: String = "",
-  file: StaticString = #file, line: UInt = #line
-) -> Never {
-  fatalError("32-bit: Unimplemented for UTF-8 support", file: file, line: line)
-}
-
 /// A Unicode string value that is a collection of characters.
 ///
 /// A string is a series of characters, such as `"Swift"`, that forms a