[stdlib] remove an extracting overload

- `RangeExpression` implicitly involves bounds checking, so this was misleading.

Author: glessard

stdlib/public/core/Span/RawSpan.swift

@@ -415,14 +415,6 @@ extension RawSpan {
   ///
   /// - Complexity: O(1)
   @unsafe
-  @_alwaysEmitIntoClient
-  @lifetime(self)
-  public func _extracting(
-    unchecked bounds: some RangeExpression<Int>
-  ) -> Self {
-    unsafe _extracting(unchecked: bounds.relative(to: byteOffsets))
-  }
-
   @_alwaysEmitIntoClient
   @lifetime(self)
   public func _extracting(

stdlib/public/core/Span/Span.swift

@@ -583,14 +583,6 @@ extension Span where Element: ~Copyable {
   ///
   /// - Complexity: O(1)
   @unsafe
-  @_alwaysEmitIntoClient
-  @lifetime(self)
-  public func _extracting(
-    unchecked bounds: some RangeExpression<Index>
-  ) -> Self {
-    unsafe _extracting(unchecked: bounds.relative(to: indices))
-  }
-
   @_alwaysEmitIntoClient
   @lifetime(self)
   public func _extracting(

test/stdlib/Span/RawSpanTests.swift

@@ -155,7 +155,7 @@ suite.test("_extracting() functions")
     let sub1 = span._extracting(0..<2)
     let sub2 = span._extracting(..<2)
     let sub3 = span._extracting(...)
-    let sub4 = span._extracting(unchecked: 2...)
+    let sub4 = span._extracting(2...)
 
     sub1.withUnsafeBytes { p1 in
       sub2.withUnsafeBytes { p2 in

test/stdlib/Span/SpanTests.swift

@@ -353,7 +353,7 @@ suite.test("_extracting() functions")
     let sub1 = span._extracting(0..<2)
     let sub2 = span._extracting(..<2)
     let sub3 = span._extracting(...)
-    let sub4 = span._extracting(unchecked: 2...)
+    let sub4 = span._extracting(2...)
     expectTrue(sub1._elementsEqual(sub2))
     expectTrue(sub3._elementsEqual(span))
     expectFalse(sub4._elementsEqual(sub3))