Disallow phase inconsitent inline parameters

Author: nicolasstucki

compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala

@@ -88,8 +88,6 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
     tree match {
       case Quoted(_) | Spliced(_)  =>
         tree
-      case tree: RefTree if tree.symbol.isAllOf(InlineParam) =>
-        tree
       case _: This =>
         assert(checkSymLevel(tree.symbol, tree.tpe, tree.sourcePos).isEmpty)
         tree
@@ -197,10 +195,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
     case Some(l) =>
       l == level ||
         level == -1 && (
-            // here we assume that Splicer.canBeSpliced was true before going to level -1,
-            // this implies that all non-inline arguments are quoted and that the following two cases are checked
-            // on inline parameters or type parameters.
-            sym.is(Param) ||
+          // TODO: Is this still needed?
             sym.isClass // reference to this in inline methods
           )
     case None =>

compiler/src/dotty/tools/dotc/transform/TreeMapWithStages.scala

@@ -19,7 +19,6 @@ import dotty.tools.dotc.util.Spans._
 import dotty.tools.dotc.util.{Property, SourcePosition}
 import dotty.tools.dotc.transform.SymUtils._
 import dotty.tools.dotc.typer.Implicits.SearchFailureType
-import dotty.tools.dotc.typer.Inliner
 
 import scala.collection.mutable
 import scala.annotation.constructorOnly

tests/neg/old-inline-param-macro.scala

@@ -0,0 +1,11 @@
+import scala.quoted._
+
+inline def old(inline x: Int): Int =
+  ${ oldImpl(x) } // error
+
+private def oldImpl(x: Int): Expr[Int] = ???
+
+inline def `new`(inline x: Int): Int =
+    ${ newImpl('x) }
+
+private def newImpl(x: Expr[Int]): Expr[Int] = ???