Migrate project to Xcode 11.4.

Author: objecthub

README.md

@@ -3,7 +3,7 @@
 
 [![Platform: macOS](https://img.shields.io/badge/Platform-macOS-blue.svg?style=flat)](https://developer.apple.com/osx/)
 [![Language: Swift 5.1](https://img.shields.io/badge/Language-Swift%205.1-green.svg?style=flat)](https://developer.apple.com/swift/)
-[![IDE: Xcode 11.3](https://img.shields.io/badge/IDE-Xcode%2011.3-orange.svg?style=flat)](https://developer.apple.com/xcode/)
+[![IDE: Xcode 11.4](https://img.shields.io/badge/IDE-Xcode%2011.4-orange.svg?style=flat)](https://developer.apple.com/xcode/)
 [![Carthage: compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage)
 [![License: Apache](http://img.shields.io/badge/License-Apache-lightgrey.svg?style=flat)](https://raw.githubusercontent.com/objecthub/swift-lispkit/master/LICENSE)
 
@@ -285,7 +285,7 @@ command-line tool, all that is needed is the Swift Package Manager. For compilin
 the command-line tool directly in Xcode, the Swift Package Manager is not needed.
 
 - [Swift 5.1](https://developer.apple.com/swift/)
-- [Xcode 11.3](https://developer.apple.com/xcode/)
+- [Xcode 11.4](https://developer.apple.com/xcode/)
 - [Swift Package Manager](https://swift.org/package-manager/)
 - [NumberKit](http://github.com/objecthub/swift-numberkit)
 - [MarkdownKit](http://github.com/objecthub/swift-markdownkit)

Sources/LispKit/Graphics/Drawing.swift

@@ -136,7 +136,7 @@ public final class Drawing: NativeObject {
     // Define a media box
     var mediaBox = NSRect(x: 0, y: 0, width: Double(width), height: Double(height))
     // Create a core graphics context suitable for drawing the image into a PDF file
-    var pdfInfo = NSMutableDictionary()
+    let pdfInfo = NSMutableDictionary()
     if let title = title {
       pdfInfo[kCGPDFContextTitle] = title
     }

Sources/LispKit/Graphics/DrawingDocument.swift

@@ -93,7 +93,7 @@ public final class DrawingDocument {
       return false
     }
     // Define PDF document information
-    var pdfInfo: NSMutableDictionary = [
+    let pdfInfo: NSMutableDictionary = [
       kCGPDFContextAllowsPrinting: (self.allowsPrinting ? kCFBooleanTrue : kCFBooleanFalse) as Any,
       kCGPDFContextAllowsCopying : (self.allowsCopying ? kCFBooleanTrue : kCFBooleanFalse) as Any
     ]

Sources/LispKit/Runtime/GarbageCollector.swift

@@ -121,7 +121,7 @@ public final class GarbageCollector: ObjectMarker {
     switch expr {
       case .pair(_, _), .box(_), .mpair(_), .array(_), .vector(_), .record(_), .table(_),
            .promise(_), .values(_), .procedure(_), .special(_), .tagged(_, _), .error(_),
-           .syntax(_):
+           .syntax(_, _):
         self.backlog.append(expr)
       default:
         break

Sources/LispKit/Runtime/Instruction.swift

@@ -578,10 +578,10 @@ public enum Instruction: CustomStringConvertible {
         return "push_char \(char)"
       case .pack(let n):
         return "pack \(n)"
-      case .unpack(let n):
-        return "unpack \(n)"
+      case .unpack(let n, let all):
+        return "unpack \(n), \(all ? "given" : "all")"
       case .makeClosure(let i, let n, let index):
-        return "make_closure \(i),\(n),\(index)"
+        return "make_closure \(i), \(n), \(index)"
       case .makePromise:
         return "make_promise"
       case .makeStream: