Fix warnings for the rest of stdlib

Author: dingobye

stdlib/public/SDK/AppKit/AppKit_FoundationExtensions.swift

@@ -14,7 +14,7 @@ import Foundation
 @_exported import AppKit
 
 // NSCollectionView extensions
-public extension IndexPath {
+extension IndexPath {
 
     /// Initialize for use with `NSCollectionView`.
     public init(item: Int, section: Int) {
@@ -51,7 +51,7 @@ public extension IndexPath {
 
 }
 
-public extension URLResourceValues {
+extension URLResourceValues {
     /// Returns all thumbnails as a single NSImage.
     @available(macOS 10.10, *)
     public var thumbnail : NSImage? {

stdlib/public/SDK/CloudKit/NestedNames.swift

@@ -16,7 +16,7 @@
 
 @nonobjc
 @available(macOS 10.10, iOS 8.0, watchOS 3.0, *)
-public extension CKContainer {
+extension CKContainer {
     @available(swift 4.2)
     public enum Application {
         public typealias Permissions = CKContainer_Application_Permissions

stdlib/public/SDK/CoreGraphics/CoreGraphics.swift

@@ -429,10 +429,10 @@ public extension CGRect {
   }
 
   @available(*, unavailable, renamed: "minX")
-  public var x: CGFloat { return minX }
+  var x: CGFloat { return minX }
 
   @available(*, unavailable, renamed: "minY")
-  public var y: CGFloat { return minY }
+  var y: CGFloat { return minY }
 }
 
 extension CGRect : CustomReflectable {

stdlib/public/SDK/Intents/INIntent.swift

@@ -17,7 +17,7 @@ import Foundation
 
 public protocol _INIntentSetImageKeyPath { }
 
-public extension _INIntentSetImageKeyPath {
+extension _INIntentSetImageKeyPath {
 
     @available(iOS 12.0, watchOS 5.0, macOS 10.14, *)
     public func setImage<Value>(_ image: INImage?, forParameterNamed parameterName: KeyPath<Self, Value>) {

stdlib/public/core/Codable.swift.gyb

@@ -1324,7 +1324,7 @@ internal struct _GenericIndexKey : CodingKey {
   }
 }
 
-public extension DecodingError {
+extension DecodingError {
   /// Returns a new `.dataCorrupted` error using a constructed coding path and
   /// the given debug description.
   ///
@@ -2058,7 +2058,7 @@ extension Dictionary : Decodable where Key : Decodable, Value : Decodable {
 
 // Default implementation of encodeConditional(_:forKey:) in terms of
 // encode(_:forKey:)
-public extension KeyedEncodingContainerProtocol {
+extension KeyedEncodingContainerProtocol {
   @inlinable // FIXME(sil-serialize-all)
   public mutating func encodeConditional<T : AnyObject & Encodable>(
     _ object: T, forKey key: Key) throws
@@ -2069,7 +2069,7 @@ public extension KeyedEncodingContainerProtocol {
 
 // Default implementation of encodeIfPresent(_:forKey:) in terms of
 // encode(_:forKey:)
-public extension KeyedEncodingContainerProtocol {
+extension KeyedEncodingContainerProtocol {
 % for type in codable_types:
   @inlinable // FIXME(sil-serialize-all)
   public mutating func encodeIfPresent(
@@ -2091,7 +2091,7 @@ public extension KeyedEncodingContainerProtocol {
 
 // Default implementation of decodeIfPresent(_:forKey:) in terms of
 // decode(_:forKey:) and decodeNil(forKey:)
-public extension KeyedDecodingContainerProtocol {
+extension KeyedDecodingContainerProtocol {
 % for type in codable_types:
   @inlinable // FIXME(sil-serialize-all)
   public func decodeIfPresent(
@@ -2115,7 +2115,7 @@ public extension KeyedDecodingContainerProtocol {
 
 // Default implementation of encodeConditional(_:) in terms of encode(_:),
 // and encode(contentsOf:) in terms of encode(_:) loop.
-public extension UnkeyedEncodingContainer {
+extension UnkeyedEncodingContainer {
   @inlinable // FIXME(sil-serialize-all)
   public mutating func encodeConditional<T : AnyObject & Encodable>(
     _ object: T) throws
@@ -2146,7 +2146,7 @@ public extension UnkeyedEncodingContainer {
 
 // Default implementation of decodeIfPresent(_:) in terms of decode(_:) and
 // decodeNil()
-public extension UnkeyedDecodingContainer {
+extension UnkeyedDecodingContainer {
 % for type in codable_types:
   @inlinable // FIXME(sil-serialize-all)
   public mutating func decodeIfPresent(