Replace remaining uses of <<< operator with .send (#1451)

After merging #1444 there are still a few uses of `<<<` left, which should be cleaned up. This fixes remaining deprecation warnings caused by the use of `<<<`.

Author: MaxDesiatov

Tests/SwiftDriverTests/CachingBuildTests.swift

@@ -148,9 +148,7 @@ final class CachingBuildTests: XCTestCase {
     try withTemporaryDirectory { path in
       let main = path.appending(component: "testCachingBuildJobs.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import C;"
-        $0 <<< "import E;"
-        $0 <<< "import G;"
+        $0.send("import C;import E;import G;")
       }
       let casPath = path.appending(component: "cas")
       let swiftModuleInterfacesPath: AbsolutePath =
@@ -278,9 +276,7 @@ final class CachingBuildTests: XCTestCase {
     try withTemporaryDirectory { path in
       let main = path.appending(component: "testExplicitModuleVerifyInterfaceJobs.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import C;"
-        $0 <<< "import E;"
-        $0 <<< "import G;"
+        $0.send("import C;import E;import G;")
       }
 
       let swiftModuleInterfacesPath: AbsolutePath =
@@ -427,9 +423,7 @@ final class CachingBuildTests: XCTestCase {
       try localFileSystem.createDirectory(moduleCachePath)
       let main = path.appending(component: "testCachingBuild.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import C;"
-        $0 <<< "import E;"
-        $0 <<< "import G;"
+        $0.send("import C;import E;import G;")
       }
 
       let cHeadersPath: AbsolutePath =
@@ -477,17 +471,17 @@ final class CachingBuildTests: XCTestCase {
       let foo = path.appending(component: "foo.swift")
       let casPath = path.appending(component: "cas")
       try localFileSystem.writeFileContents(foo) {
-        $0 <<< "extension Profiler {"
-        $0 <<< "    public static let count: Int = 42"
-        $0 <<< "}"
+        $0.send("extension Profiler {")
+        $0.send("    public static let count: Int = 42")
+        $0.send("}")
       }
       let fooHeader = path.appending(component: "foo.h")
       try localFileSystem.writeFileContents(fooHeader) {
-        $0 <<< "struct Profiler { void* ptr; };"
+        $0.send("struct Profiler { void* ptr; };")
       }
       let main = path.appending(component: "main.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import Foo"
+        $0.send("import Foo")
       }
       let sdkArgumentsForTesting = (try? Driver.sdkArgumentsForTesting()) ?? []
 
@@ -546,9 +540,7 @@ final class CachingBuildTests: XCTestCase {
     try withTemporaryDirectory { path in
       let main = path.appending(component: "testDependencyScanning.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import C;"
-        $0 <<< "import E;"
-        $0 <<< "import G;"
+        $0.send("import C;import E;import G;")
       }
 
       let cHeadersPath: AbsolutePath =

Tests/SwiftDriverTests/ExplicitModuleBuildTests.swift

@@ -362,9 +362,7 @@ final class ExplicitModuleBuildTests: XCTestCase {
     try withTemporaryDirectory { path in
       let main = path.appending(component: "testExplicitModuleVerifyInterfaceJobs.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import C;"
-        $0 <<< "import E;"
-        $0 <<< "import G;"
+        $0.send("import C;import E;import G;")
       }
 
       let swiftModuleInterfacesPath: AbsolutePath =
@@ -1029,17 +1027,17 @@ final class ExplicitModuleBuildTests: XCTestCase {
       try localFileSystem.createDirectory(FooInstallPath)
       let foo = path.appending(component: "foo.swift")
       try localFileSystem.writeFileContents(foo) {
-        $0 <<< "extension Profiler {"
-        $0 <<< "    public static let count: Int = 42"
-        $0 <<< "}"
+        $0.send("extension Profiler {")
+        $0.send("    public static let count: Int = 42")
+        $0.send("}")
       }
       let fooHeader = path.appending(component: "foo.h")
       try localFileSystem.writeFileContents(fooHeader) {
-        $0 <<< "struct Profiler { void* ptr; };"
+        $0.send("struct Profiler { void* ptr; };")
       }
       let main = path.appending(component: "main.swift")
       try localFileSystem.writeFileContents(main) {
-        $0 <<< "import Foo"
+        $0.send("import Foo")
       }
       let sdkArgumentsForTesting = (try? Driver.sdkArgumentsForTesting()) ?? []
 

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -2200,8 +2200,9 @@ final class SwiftDriverTests: XCTestCase {
 
     do {
       try withTemporaryDirectory { path in
-        try localFileSystem.writeFileContents(
-          path.appending(components: "wasi", "static-executable-args.lnk")) { $0 <<< "garbage" }
+        try localFileSystem.writeFileContents(path.appending(components: "wasi", "static-executable-args.lnk")) {
+          $0.send("garbage")
+        }
         // Wasm executable linking
         var driver = try Driver(args: commonArgs + ["-emit-executable", "-Ounchecked",
                                                     "-target", "wasm32-unknown-wasi",