Synchronize Data.swift from the overlay

[phausler]

This pulls in the fixes for:
Guard Data access to NSData._isCompact under availability guards
Ensure that hashing data with zero bytes avoids empty allocations and fix bridged empty data hashes from de-referencing null values (#12509)
Data slice mutation support (#11939)

[phausler]

@swift-ci please test

[ianpartridge]

Foundation/Data.swift:1645:9: error: use of unresolved identifier '_withStackOrHeapBuffer'
        _withStackOrHeapBuffer(hashRange.count + 1) { buffer in
        ^~~~~~~~~~~~~~~~~~~~~~
Foundation/Data.swift:32:12: error: value of type 'NSData' has no member '_isCompact'
    return data._isCompact()
           ^~~~ ~~~~~~~~~~
Foundation/Data.swift:1496:9: error: use of unresolved identifier '_withStackOrHeapBuffer'
        _withStackOrHeapBuffer(estimatedCount) { allocation in
        ^~~~~~~~~~~~~~~~~~~~~~
Foundation/Data.swift:1579:9: error: use of unresolved identifier '_withStackOrHeapBuffer'
        _withStackOrHeapBuffer(totalCount) { conditionalBuffer in
        ^~~~~~~~~~~~~~~~~~~~~~

[phausler]

I guess it is missing the helper func: will add it to this later today

[parkera]

@phausler Let's get this one in

[phausler]

@swift-ci please test and merge

[shahmishal]

@swift-ci please test and merge

[shahmishal]

Foundation/Data.swift:32:12: error: value of type 'NSData' has no member '_isCompact'
    return data._isCompact()
           ^~~~ ~~~~~~~~~~
Foundation/HTTPCookie.swift:252:74: warning: 'characters' is deprecated: Please use String or Substring directly
            secureString = properties[.secure] as? String, !secureString.characters.isEmpty

[phausler]

@swift-ci please test and merge

[shahmishal]

@swift-ci please test and merge