Depend on Kotlin's implementation of parsing JVM target

Author: Omar El Halabi

server/src/main/kotlin/org/javacs/kt/compiler/Compiler.kt

@@ -382,25 +382,10 @@ private class CompilationEnvironment(
     }
 
     fun updateConfiguration(config: CompilerConfiguration) {
-        jvmTargetFrom(config.jvm.target)
+        JvmTarget.fromString(config.jvm.target)
             ?.let { environment.configuration.put(JVMConfigurationKeys.JVM_TARGET, it) }
     }
 
-    private fun jvmTargetFrom(target: String): JvmTarget? = when (target) {
-        // See https://github.com/JetBrains/kotlin/blob/master/compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmTarget.kt
-        "default" -> JvmTarget.DEFAULT
-        "1.6" -> JvmTarget.JVM_1_6
-        "1.8" -> JvmTarget.JVM_1_8
-        "9" -> JvmTarget.JVM_9
-        "10" -> JvmTarget.JVM_10
-        "11" -> JvmTarget.JVM_11
-        "12" -> JvmTarget.JVM_12
-        "13" -> JvmTarget.JVM_13
-        "14" -> JvmTarget.JVM_14
-        "15" -> JvmTarget.JVM_15
-        else -> null
-    }
-
     fun createContainer(sourcePath: Collection<KtFile>): Pair<ComponentProvider, BindingTraceContext> {
         val trace = CliBindingTrace()
         val container = TopDownAnalyzerFacadeForJVM.createContainer(