Removed last uses of @warn_unused_result

Author: tanadeau

lib/Sema/TypeChecker.h

@@ -1831,8 +1831,7 @@ class TypeChecker final : public LazyResolver {
   /// Checks an "ignored" expression to see if it's okay for it to be ignored.
   ///
   /// An ignored expression is one that is not nested within a larger
-  /// expression or statement. The warning from the \@warn_unused_result
-  /// attribute is produced here.
+  /// expression or statement.
   void checkIgnoredExpr(Expr *E);
 
   // Emits a diagnostic, if necessary, for a reference to a declaration

stdlib/public/core/CollectionAlgorithms.swift.gyb

@@ -322,7 +322,7 @@ extension ${Self} where Self.Iterator.Element : Comparable {
   /// - Returns: A sorted array of the ${sequenceKind}'s elements.
   ///
   /// - SeeAlso: `sorted(isOrderedBefore:)`
-  @warn_unused_result(${'mutable_variant: "sort"' if Self == 'MutableCollection' else ''})
+  /// ${'- MutatingVariant: sort' if Self == 'MutableCollection' else ''}
   public func sorted() -> [Iterator.Element] {
     var result = ContiguousArray(self)
     result.sort()
@@ -396,7 +396,7 @@ ${orderingExplanation}
   /// - Returns: A sorted array of the ${sequenceKind}'s elements.
   ///
   /// - SeeAlso: `sorted()`
-  @warn_unused_result(${'mutable_variant: "sort"' if Self == 'MutableCollection' else ''})
+  /// ${'- MutatingVariant: sort' if Self == 'MutableCollection' else ''}
   public func sorted(
     isOrderedBefore:
       @noescape (${IElement}, ${IElement}) -> Bool

test/1_stdlib/Runtime.swift

@@ -9,7 +9,6 @@ import StdlibUnittest
 import SwiftShims
 
 
-@warn_unused_result
 @_silgen_name("swift_demangle")
 public
 func _stdlib_demangleImpl(
@@ -20,7 +19,6 @@ func _stdlib_demangleImpl(
   flags: UInt32
 ) -> UnsafeMutablePointer<CChar>?
 
-@warn_unused_result
 func _stdlib_demangleName(_ mangledName: String) -> String {
   return mangledName.nulTerminatedUTF8.withUnsafeBufferPointer {
     (mangledNameUTF8) in

test/IDE/print_ast_tc_decls.swift

@@ -1284,33 +1284,6 @@ struct d2900_TypeSugar1 {
 // PASS_COMMON-NEXT: {{^}}  init(){{$}}
 // PASS_COMMON-NEXT: {{^}}}{{$}}
 
-// @warn_unused_result attribute
-public struct ArrayThingy {
-    // PASS_PRINT_AST: @warn_unused_result(mutable_variant: "sort")
-    // PASS_PRINT_AST-NEXT: public func sort() -> ArrayThingy
-    @warn_unused_result(mutable_variant: "sort")
-    public func sort() -> ArrayThingy { return self }
-
-    public mutating func sort() { }
-
-    // PASS_PRINT_AST: @warn_unused_result(message: "dummy", mutable_variant: "reverseInPlace")
-    // PASS_PRINT_AST-NEXT: public func reverse() -> ArrayThingy
-    @warn_unused_result(message: "dummy", mutable_variant: "reverseInPlace")
-    public func reverse() -> ArrayThingy { return self }
-
-    public mutating func reverseInPlace() { }
-
-    // PASS_PRINT_AST: @warn_unused_result
-    // PASS_PRINT_AST-NEXT: public func mineGold() -> Int
-    @warn_unused_result
-    public func mineGold() -> Int { return 0 }
-
-    // PASS_PRINT_AST: @warn_unused_result(message: "oops")
-    // PASS_PRINT_AST-NEXT: public func mineCopper() -> Int
-    @warn_unused_result(message: "oops")
-    public func mineCopper() -> Int { return 0 }
-}
-
 // @discardableResult attribute
 public struct DiscardableThingy {
     // PASS_PRINT_AST: @discardableResult

test/IDE/print_stdlib.swift

@@ -97,5 +97,4 @@ func foo(x: _Pointer) {} // Checks that this protocol actually exists.
 
 // CHECK-FREQUENT-WORD: ///
 // CHECK-FREQUENT-WORD-NOT: where Slice<Dictionary<Key, Value>> == Slice<Self>
-// CHECK-FREQUENT-WORD-NOT: @warn_unused_result
 // CHECK-COLLECTION-GROUP: extension MutableCollection