Fix #6765: Add regression test

Author: nicolasstucki

tests/run-macros/i6765.check

@@ -0,0 +1,8 @@
+{
+  val x$1: java.lang.String = "One"
+  scala.Nil.::[java.lang.String](x$1)
+}
+{
+  val x$1: java.lang.String = "One"
+  scala.Nil.::[java.lang.String](x$1)
+}

tests/run-macros/i6765/Macro_1.scala

@@ -0,0 +1,12 @@
+import scala.quoted._
+import delegate scala.quoted._
+
+delegate for Toolbox = Toolbox.make(getClass.getClassLoader)
+
+inline def crash = ${crashImpl}
+
+def crashImpl given (qctx: QuoteContext) = {
+  import qctx.tasty._  // Works if commented out
+  val res = List('{"One"}).toExprOfList  // Works if replaced with '{"One" :: Nil}
+  res.show.toExpr
+}

tests/run-macros/i6765/Test_2.scala

@@ -0,0 +1,8 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    val res = crash  // Works if these two lines are commented out at the same time
+    println(res)     // Works if these two lines are commented out at the same time
+
+    println(crash)
+  }
+}