Use Triple equality for finding matching binaries (#4270)

In swiftlang/swift-tools-support-core#300, I made `Triple` more lenient w.r.t. different spellings of macOS. Since we are using string matching for finding matching binary artifacts, that would break with differently spelled triples. This PR in conjunction with swiftlang/swift-tools-support-core#307 ensures that we are finding artifacts based on the parsed representation of triples, not their string representations.

Author: neonichu

Sources/SPMBuildCore/BinaryTarget+Extensions.swift

@@ -59,6 +59,8 @@ extension BinaryTarget {
     }
 
     public func parseArtifactArchives(for triple: Triple, fileSystem: FileSystem) throws -> [ExecutableInfo] {
+        // The host triple might contain a version which we don't want to take into account here.
+        let versionLessTriple = try triple.withoutVersion()
         // We return at most a single variant of each artifact.
         let metadata = try ArtifactsArchiveMetadata.parse(fileSystem: fileSystem, rootPath: self.artifactPath)
         // Currently we filter out everything except executables.
@@ -68,19 +70,25 @@ extension BinaryTarget {
         return executables.flatMap { entry in
             // FIXME: this filter needs to become more sophisticated
             entry.value.variants.filter {
-                let tripleStrings = $0.supportedTriples.map { $0.tripleString }
-                if triple.isDarwin() {
-                    return tripleStrings.contains(triple.tripleString(forPlatformVersion: ""))
-                } else {
-                    return tripleStrings.contains(triple.tripleString)
-                }
+                return $0.supportedTriples.contains(versionLessTriple)
             }.map{
                 ExecutableInfo(name: entry.key, executablePath: AbsolutePath($0.path, relativeTo: self.artifactPath))
             }
         }
     }
 }
 
+fileprivate extension Triple {
+    func withoutVersion() throws -> Triple {
+        if isDarwin() {
+            let stringWithoutVersion = tripleString(forPlatformVersion: "")
+            return try Triple(stringWithoutVersion)
+        } else {
+            return self
+        }
+    }
+}
+
 fileprivate extension Triple.OS {
     /// Returns a representation of the receiver that can be compared with platform strings declared in an XCFramework.
     var asXCFrameworkPlatformString: String? {