Fix script classpath utility functions that use classpath filtering by "keys"

The problem was that only the first matching classpath entry were used.
The problem was reported by @lion7 on github (https://github.com/JetBrains/kotlin/commit/67ad3773de2b12f7e1d29e00151b997a4f6373ba#commitcomment-34443927)

libraries/scripting/jvm-host-test/test/kotlin/script/experimental/jvmhost/test/ClassPathTest.kt

@@ -16,6 +16,7 @@ import java.util.jar.JarOutputStream
 import java.util.jar.Manifest
 import kotlin.script.experimental.jvm.util.classPathFromTypicalResourceUrls
 import kotlin.script.experimental.jvm.util.classpathFromClassloader
+import kotlin.script.experimental.jvm.util.scriptCompilationClasspathFromContextOrNull
 
 class ClassPathTest : TestCase() {
 
@@ -57,6 +58,28 @@ class ClassPathTest : TestCase() {
             Assert.assertTrue(cp.contains(File(root1, el).canonicalFile))
         }
     }
+
+    @Test
+    fun testFilterClasspath() {
+        val tempDir = createTempDir().canonicalFile
+        try {
+            val files = listOf(
+                File(tempDir, "projX/classes"),
+                File(tempDir, "projX/test-classes"),
+                File(tempDir, "projY/classes")
+            )
+            files.forEach { it.mkdirs() }
+
+            val classloader = URLClassLoader(files.map { it.toURI().toURL() }.toTypedArray(), null)
+
+            val classpath =
+                scriptCompilationClasspathFromContextOrNull("projX", classLoader = classloader)!!.map { it.toRelativeString(tempDir) }
+
+            Assert.assertEquals(files.dropLast(1).map { it.toRelativeString(tempDir) }, classpath)
+        } finally {
+            tempDir.deleteRecursively()
+        }
+    }
 }
 
 private val emulatedCollectionFiles = arrayOf(