[4.2][stdlib] undeprecate countable range (#16361)

* Undeprecate Countable*Range

* Remove check for deprecation warnings

Author: airspeedswift

stdlib/public/core/ClosedRange.swift

@@ -505,6 +505,5 @@ extension ClosedRange {
 @available(*, deprecated, renamed: "ClosedRange.Index")
 public typealias ClosedRangeIndex<T> = ClosedRange<T>.Index where T: Strideable, T.Stride: SignedInteger
 
-@available(*, deprecated: 4.2, renamed: "ClosedRange")
 public typealias CountableClosedRange<Bound: Strideable> = ClosedRange<Bound>
   where Bound.Stride : SignedInteger

stdlib/public/core/Range.swift

@@ -910,10 +910,8 @@ extension Range {
   }
 }
 
-@available(*, deprecated, renamed: "Range")
 public typealias CountableRange<Bound: Strideable> = Range<Bound>
   where Bound.Stride : SignedInteger
 
-@available(*, deprecated: 4.2, renamed: "PartialRangeFrom")
 public typealias CountablePartialRangeFrom<Bound: Strideable> = PartialRangeFrom<Bound>
   where Bound.Stride : SignedInteger

test/Compatibility/stdlib_generic_typealiases.swift

@@ -2,8 +2,7 @@
 
 struct RequiresStrideable<T: Strideable> { }
 
-extension CountableRange { // expected-warning{{'CountableRange' is deprecated: renamed to 'Range'}}
-  // expected-note@-1{{use 'Range' instead}}{{11-25=Range}}
+extension CountableRange {
   func testStrideable() {
     _ = RequiresStrideable<Bound>()
   }
@@ -24,7 +23,5 @@ extension DictionaryIndex {
 }
 
 extension CountableRange where Element == Int {
-  // expected-warning@-1{{'CountableRange' is deprecated: renamed to 'Range'}}
-  // expected-note@-2{{use 'Range' instead}}
   func getLowerBoundAsInt() -> Int { return lowerBound }
 }