Backport "Don't generate a super accessor for an inline method call" to LTS (#18974)

Backports #17598 to the LTS branch.

PR submitted by the release tooling.
[skip ci]

Author: Kordyjan

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

@@ -153,8 +153,11 @@ class SuperAccessors(thisPhase: DenotTransformer) {
         }
     }
 
-    val needAccessor = name.isTermName && (
-      clazz != currentClass || !validCurrentClass || mix.name.isEmpty && clazz.is(Trait))
+    val needAccessor =
+      name.isTermName                // Types don't need super accessors
+      && !sym.isEffectivelyErased    // Erased and concrete inline methods are not called at runtime
+      && !sym.isInlineMethod         //   so they don't need superaccessors.
+      && (clazz != currentClass || !validCurrentClass || mix.name.isEmpty && clazz.is(Trait))
 
     if (needAccessor) atPhase(thisPhase.next)(superAccessorCall(sel, mix.name))
     else sel

tests/pos/i17584a.scala

@@ -0,0 +1,7 @@
+
+import language.experimental.erasedDefinitions
+trait A:
+  erased def g = 1
+trait B extends A:
+  erased def f = super.g
+class C extends B

tests/run/i17584.scala

@@ -0,0 +1,10 @@
+trait A:
+  inline def g = 1
+trait B extends A:
+  def f = super.g
+class C extends B
+
+@main def Test =
+  val c = C()
+  assert(c.f == 1)
+

tests/run/i17584a.scala

@@ -0,0 +1,11 @@
+trait T:
+  def g = 2
+trait A extends T:
+  inline override def g = 1
+trait B extends A:
+  def f = super.g
+class C extends B
+
+@main def Test =
+  val c = C()
+  assert(c.f == 1)