Make Applications#resolveMapped preserve annotations

Overloading may create a temporary symbol via `Applications#resolveMapped`, but
before this commit, this symbol did not carry the annotations from the original
symbol. This meant in particular that `isInlineable` would always return false
for them. This matters because during the course of overloading resolution we
might call `ProtoTypes.Compatibility#constrainResult` which special-cases
transparent inline methods.

Fixes a regression in Monocle introduced in the previous commit.

wip

Author: smarter

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -2503,6 +2503,7 @@ trait Applications extends Compatibility {
       if t.exists && alt.symbol.exists then
         val (trimmed, skipped) = trimParamss(t.stripPoly, alt.symbol.rawParamss)
         val mappedSym = alt.symbol.asTerm.copy(info = t)
+        mappedSym.annotations = alt.symbol.annotations
         mappedSym.rawParamss = trimmed
         val (pre, totalSkipped) = mappedAltInfo(alt.symbol) match
           case Some((pre, prevSkipped)) =>

tests/pos/i21410c.scala

@@ -0,0 +1,11 @@
+class AppliedPIso[A, B]()
+case class User(age: Int)
+
+object Test:
+  extension [From, To](from: From)
+    def focus(): AppliedPIso[From, From] = ???
+    transparent inline def focus(inline lambda: (From => To)): Any = ???
+
+
+  val u = User(1)
+  val ap: AppliedPIso[User, User] = u.focus(_.age) // error