Run type inference before implicit search

Author: Alex1005a

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

@@ -4250,13 +4250,14 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
                 else formals1
               implicitArgs(formals2, argIndex + 1, pt)
 
+            val pt1 = pt.deepenProtoTrans
+            if ((pt1 `ne` pt) && (pt1 ne sharpenedPt) && constrainResult(tree.symbol, wtp, pt1)) {
+              return implicitArgs(formals, argIndex, pt1)
+            }
             val arg = inferImplicitArg(formal, tree.span.endPos)
             arg.tpe match
               case failed: AmbiguousImplicits =>
-                val pt1 = pt.deepenProtoTrans
-                if (pt1 `ne` pt) && (pt1 ne sharpenedPt) && constrainResult(tree.symbol, wtp, pt1)
-                then implicitArgs(formals, argIndex, pt1)
-                else arg :: implicitArgs(formals1, argIndex + 1, pt1)
+                arg :: implicitArgs(formals1, argIndex + 1, pt1)
               case failed: SearchFailureType =>
                 lazy val defaultArg = findDefaultArgument(argIndex)
                   .showing(i"default argument: for $formal, $tree, $argIndex = $result", typr)