[Native] Remove unused code

kotlin-native/build-tools/src/main/groovy/org/jetbrains/kotlin/NativeInteropPlugin.groovy

@@ -302,10 +302,6 @@ class NativeInteropPlugin implements Plugin<Project> {
     void apply(Project prj) {
         prj.extensions.add("kotlinNativeInterop", new NativeInteropExtension(prj))
 
-        def runtimeNativeLibsDir = new File(prj.findProject(':kotlin-native:Interop:Runtime').buildDir, 'nativelibs')
-
-        def nativeLibsDir = new File(prj.buildDir, "nativelibs")
-
         prj.configurations {
             interopStubGenerator
         }

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/bitcode/CompileToBitcode.kt

@@ -91,7 +91,7 @@ open class CompileToBitcode @Inject constructor(
                 Language.CPP ->
                     listOfNotNull("-std=c++17", "-Werror", "-O2",
                             "-Wall", "-Wextra",
-                            "-Wno-unused-parameter",  // False positives with polymorphic functions.
+                            "-Wno-unused-parameter"  // False positives with polymorphic functions.
                     )
             }
             return commonFlags + sanitizerFlags + languageFlags + compilerArgs

kotlin-native/llvmCoverageMappingC/build.gradle.kts

@@ -27,8 +27,6 @@ plugins {
 native {
     val obj = if (HostManager.hostIsMingw) "obj" else "o"
     val llvmDir = project.findProperty("llvmDir")
-    val host = rootProject.project(":kotlin-native").extra["hostName"]
-    val hostLibffiDir = rootProject.project(":kotlin-native").extra["${host}LibffiDir"]
     val cxxflags = mutableListOf(
         "--std=c++17",
         "-I${llvmDir}/include",