Merge pull request #9293 from phausler/swift-4.0-branch_safe_nsnumber

SE-0170 cherry pick for swift 4.0

Author: tkremenek

stdlib/public/SDK/Foundation/CMakeLists.txt

@@ -31,7 +31,7 @@ add_swift_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SD
   NSFastEnumeration.swift
   NSGeometry.swift
   NSIndexSet.swift
-  NSNumber.swift.gyb
+  NSNumber.swift
   NSPredicate.swift
   NSRange.swift
   NSSet.swift
@@ -47,7 +47,6 @@ add_swift_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SD
   ReferenceConvertible.swift
   String.swift
   TimeZone.swift
-  TypePreservingNSNumber.mm
   URL.swift
   URLComponents.swift
   URLRequest.swift