Update TestProcess.swift

Author: AZero13

Tests/Foundation/Tests/TestProcess.swift

@@ -12,7 +12,12 @@ class TestProcess : XCTestCase {
     func test_exit0() throws {
         let process = Process()
         let executableURL = xdgTestHelperURL()
-        process.executableURL = executableURL
+        if #available(OSX 10.13, *) {
+            process.executableURL = executableURL
+        } else {
+            // Fallback on earlier versions
+            process.launchPath = executableURL.path
+        }
         XCTAssertEqual(process.launchPath, executableURL.path)
         process.arguments = ["--exit", "0"]
         try process.run()
@@ -966,7 +971,12 @@ internal func runTask(_ arguments: [String], environment: [String: String]? = ni
     let process = Process()
 
     var arguments = arguments
-    process.executableURL = URL(fileURLWithPath:arguments.removeFirst())
+    if #available(OSX 10.13, *) {
+        process.executableURL = URL(fileURLWithPath:arguments.removeFirst())
+    } else {
+        // Fallback on earlier versions
+        process.launchPath = arguments.removeFirst()
+    }
     process.arguments = arguments
     // Darwin Foundation doesnt allow .environment to be set to nil although the documentation
     // says it is an optional. https://developer.apple.com/documentation/foundation/process/1409412-environment