Handle macro dependencies through class of this

Fixes #18393

[Cherry-picked 671f755]

Author: nicolasstucki

compiler/src/dotty/tools/dotc/inlines/Inliner.scala

@@ -1067,6 +1067,8 @@ class Inliner(val call: tpd.Tree)(using Context):
         tree match {
           case tree: RefTree if tree.isTerm && level == -1 && tree.symbol.isDefinedInCurrentRun && !tree.symbol.isLocal =>
             foldOver(tree.symbol :: syms, tree)
+          case _: This if level == -1 && tree.symbol.isDefinedInCurrentRun =>
+            tree.symbol :: syms
           case _: TypTree => syms
           case _ => foldOver(syms, tree)
         }

tests/pos-macros/i18393/Inline_2.scala

@@ -0,0 +1,8 @@
+package user
+
+import defn.Macro
+
+object Inline extends Macro {
+  inline def callMacro(): Int =
+    ${ this.impl() }
+}

tests/pos-macros/i18393/Macro_1.scala

@@ -0,0 +1,7 @@
+package defn
+
+import scala.quoted.*
+
+abstract class Macro {
+  def impl()(using Quotes): Expr[Int] = '{1}
+}

tests/pos-macros/i18393/Test_2.scala

@@ -0,0 +1,5 @@
+package user
+
+object Test {
+  Inline.callMacro()
+}