Minor Data updates (swiftlang#1704)

Author: jmschonfeld

Sources/FoundationEssentials/Data/Data+Base64.swift

@@ -608,7 +608,7 @@ extension Base64 {
 
         let outputLength = ((inBuffer.count + 3) / 4) * 3
 
-        let pointer = malloc(outputLength)
+        let pointer = __DataStorage.allocate(outputLength, false)
         let other = pointer?.bindMemory(to: UInt8.self, capacity: outputLength)
         let target = UnsafeMutableBufferPointer(start: other, count: outputLength)
         var length = outputLength

Sources/FoundationEssentials/Data/Data.swift

@@ -48,7 +48,9 @@
 @usableFromInline let memcmp = WASILibc.memcmp
 #endif
 
+#if !NO_CSHIMS
 internal import _FoundationCShims
+#endif
 import Builtin
 
 #if canImport(Darwin)

Sources/FoundationEssentials/Platform.swift

@@ -45,7 +45,6 @@ fileprivate let _pageSize: Int = Int(getpagesize())
 internal import CoreFoundation_Private
 #endif
 
-
 package struct Platform {
     static var pageSize: Int {
         _pageSize