Update manifest to tools version 5

This updates the manifest to tools version 5 so we can use the new API
for setting linker flags. There is also a version-specific manifest for
older Swift 4.2 clients.

(cherry picked from commit c7333ce)

Package.swift

@@ -1,13 +1,7 @@
-// swift-tools-version:4.0
+// swift-tools-version:5.0
 
 // This file defines Swift package manager support for llbuild. See:
 //  https://github.com/apple/swift-package-manager/tree/master/Documentation
-//
-// You can build using:
-//
-// ```shell
-// swift build -Xlinker -lsqlite3 -Xlinker -lncurses $(utils/generate-version-h.sh)
-// ```
 
 import PackageDescription
 
@@ -61,7 +55,8 @@ let package = Package(
         .target(
             name: "llbuildCore",
             dependencies: ["llbuildBasic"],
-            path: "lib/Core"
+            path: "lib/Core",
+            linkerSettings: [.linkedLibrary("sqlite3")]
         ),
         .target(
             name: "llbuildBuildSystem",
@@ -117,7 +112,8 @@ let package = Package(
 
         .target(
             name: "llvmSupport",
-            path: "lib/llvm/Support"
+            path: "lib/llvm/Support",
+            linkerSettings: [.linkedLibrary("ncurses")]
         ),
     ],
     cxxLanguageStandard: .cxx14

Package@swift-4.2.swift

@@ -0,0 +1,123 @@
+// swift-tools-version:4.2.0
+
+// This file defines Swift package manager support for llbuild. See:
+//  https://github.com/apple/swift-package-manager/tree/master/Documentation
+
+import PackageDescription
+
+let package = Package(
+    name: "llbuild",
+    products: [
+        .library(
+            name: "libllbuild",
+            targets: ["libllbuild"]),
+        .library(
+            name: "llbuildSwift",
+            targets: ["llbuildSwift"]),
+    ],
+    targets: [
+        /// The llbuild testing tool.
+        .target(
+            name: "llbuild",
+            dependencies: ["llbuildCommands"],
+            path: "products/llbuild"
+        ),
+
+        /// The custom build tool used by the Swift package manager.
+        .target(
+            name: "swift-build-tool",
+            dependencies: ["llbuildBuildSystem"],
+            path: "products/swift-build-tool"
+        ),
+
+        /// The custom build tool used by the Swift package manager.
+        .target(
+            name: "llbuildSwift",
+            dependencies: ["libllbuild"],
+            path: "products/llbuildSwift",
+            exclude: ["llbuild.swift"]
+        ),
+
+        /// The public llbuild API.
+        .target(
+            name: "libllbuild",
+            dependencies: ["llbuildCore", "llbuildBuildSystem"],
+            path: "products/libllbuild"
+        ),
+
+        // MARK: Components
+
+        .target(
+            name: "llbuildBasic",
+            dependencies: ["llvmSupport"],
+            path: "lib/Basic"
+        ),
+        .target(
+            name: "llbuildCore",
+            dependencies: ["llbuildBasic"],
+            path: "lib/Core"
+        ),
+        .target(
+            name: "llbuildBuildSystem",
+            dependencies: ["llbuildCore"],
+            path: "lib/BuildSystem"
+        ),
+        .target(
+            name: "llbuildNinja",
+            dependencies: ["llbuildBasic"],
+            path: "lib/Ninja"
+        ),
+        .target(
+            name: "llbuildCommands",
+            dependencies: ["llbuildCore", "llbuildBuildSystem", "llbuildNinja"],
+            path: "lib/Commands"
+        ),
+
+        // MARK: Test Targets
+
+        .target(
+            name: "llbuildBasicTests",
+            dependencies: ["llbuildBasic", "gtest"],
+            path: "unittests/Basic"),
+        .target(
+            name: "llbuildCoreTests",
+            dependencies: ["llbuildCore", "gtest"],
+            path: "unittests/Core"),
+        .target(
+            name: "llbuildBuildSystemTests",
+            dependencies: ["llbuildBuildSystem", "gtest"],
+            path: "unittests/BuildSystem"),
+        .target(
+            name: "llbuildNinjaTests",
+            dependencies: ["llbuildNinja", "gtest"],
+            path: "unittests/Ninja"),
+
+        // MARK: GoogleTest
+
+        .target(
+            name: "gtest",
+            path: "utils/unittest/googletest/src",
+            exclude: [
+                "gtest-death-test.cc",
+                "gtest-filepath.cc",
+                "gtest-port.cc",
+                "gtest-printers.cc",
+                "gtest-test-part.cc",
+                "gtest-typed-test.cc",
+                "gtest.cc",
+            ]),
+
+        // MARK: Ingested LLVM code.
+        .target(
+          name: "llvmDemangle",
+          path: "lib/llvm/Demangle"
+        ),
+
+        .target(
+            name: "llvmSupport",
+            dependencies: ["llvmDemangle"],
+            path: "lib/llvm/Support"
+        ),
+    ],
+    cxxLanguageStandard: .cxx14
+)