Change some remaining llvm versions

Author: mattisboeckle

effekt/jvm/src/main/scala/effekt/EffektConfig.scala

@@ -69,7 +69,7 @@ class EffektConfig(args: Seq[String]) extends REPLConfig(args.takeWhile(_ != "--
   val llvmVersion: ScallopOption[String] = opt[String](
     "llvm-version",
     descr = "the llvm version that should be used to compile the generated programs (only necessary if backend is llvm, defaults to 15)",
-    default = Some(sys.env.getOrElse("EFFEKT_LLVM_VERSION", "15")),
+    default = Some(sys.env.getOrElse("EFFEKT_LLVM_VERSION", "18")),
     noshort = true,
     group = advanced
   )

effekt/jvm/src/main/scala/effekt/Runner.scala

@@ -267,8 +267,8 @@ object LLVMRunner extends Runner[String] {
   override def includes(path: File): List[File] = List(path / ".." / "llvm")
 
   lazy val gccCmd = discoverExecutable(List("cc", "clang", "gcc"), List("--version"))
-  lazy val llcCmd = discoverExecutable(List("llc", "llc-15", "llc-16"), List("--version"))
-  lazy val optCmd = discoverExecutable(List("opt", "opt-15", "opt-16"), List("--version"))
+  lazy val llcCmd = discoverExecutable(List("llc", "llc-18"), List("--version"))
+  lazy val optCmd = discoverExecutable(List("opt", "opt-18"), List("--version"))
 
   def checkSetup(): Either[String, Unit] =
     gccCmd.getOrElseAborting { return Left("Cannot find gcc. This is required to use the LLVM backend.") }