Depend on kotlin-native-shared from a separate repo

Kotlin-native-shared was copied in a separate repository.
This patch removes this subproject from the K/N repo and
adds a dependency on an artifact built from this separate repo.

llvmCoverageMappingC/build.gradle

@@ -17,16 +17,8 @@
 apply plugin: "cpp"
 apply plugin: "c"
 
-buildscript {
-  ext.rootBuildDirectory = file('..')
+apply from: "${rootProject.projectDir}/gradle/kotlinGradlePlugin.gradle"
 
-  apply from: "$rootBuildDirectory/gradle/kotlinGradlePlugin.gradle"
-
-  dependencies {
-    classpath "org.jetbrains.kotlin:kotlin-stdlib:$buildKotlinVersion"
-    classpath "org.jetbrains.kotlin:kotlin-native-shared:$konanVersion"
-  }
-}
 import org.jetbrains.kotlin.konan.target.ClangArgs
 
 model {