Tests: address TODO for Windows

Now that the frontend properly consults the architecture independent
path for the Swift modules, we can address the TODO that was left to
be addressed.  This requires swiftlang/swift#42419 and
swiftlang/swift-installer-scripts#119

Author: compnerd

Tests/SwiftDriverTests/ExplicitModuleBuildTests.swift

@@ -932,23 +932,8 @@ final class ExplicitModuleBuildTests: XCTestCase {
       return (stdLibPath, stdLibPath.appending(component: "shims"))
     } else if driver.targetTriple.isWindows {
       if let sdkroot = try driver.toolchain.defaultSDKPath(driver.targetTriple) {
-        return (sdkroot
-                  .appending(component: "usr")
-                  .appending(component: "lib")
-                  .appending(component: "swift")
-                  .appending(component: "windows")
-                  // TODO(compnerd) this should be dropped, but we need to
-                  // synchronize with the frontend and installer to ensure that
-                  // everything is setup properly.  With the swiftmodule
-                  // directory structure being supported, we no longer need to
-                  // put the swiftmodules in the architecture directory, only
-                  // the import libraries.
-                  .appending(component: driver.targetTriple.archName),
-                sdkroot
-                  .appending(component: "usr")
-                  .appending(component: "lib")
-                  .appending(component: "swift")
-                  .appending(component: "shims"))
+        return (sdkroot.appending(components: "usr", "lib", "swift", "windows"),
+                sdkroot.appending(components: "usr", "lib", "swift", "shims"))
       }
       return (toolchainRootPath
                 .appending(component: "lib")