Factor FileCheck into a framework

Author: CodaFi

Package.swift

@@ -11,5 +11,13 @@ let package = Package(
   ],
   dependencies: [
     .package(url: "https://github.com/trill-lang/cllvm.git", .branch("master")),
+    .package(url: "https://github.com/trill-lang/FileCheck.git", .branch("master")),
+  ],
+  targets: [
+    .target(
+      name: "LLVM"),
+    .testTarget(
+      name: "LLVMTests",
+      dependencies: ["LLVM", "FileCheck"]),
   ]
 )

Tests/LLVMTests/ANSIColor.swift

@@ -1,5 +1,6 @@
 import LLVM
 import XCTest
+import FileCheck
 import Foundation
 
 class ConstantSpec : XCTestCase {

Tests/LLVMTests/ColoredStream.swift

@@ -1,5 +1,6 @@
 import LLVM
 import XCTest
+import FileCheck
 import Foundation
 
 class FileCheckSpec : XCTestCase {