Merge pull request #5758 from dotty-staging/fix-#3955

Fix #3955: Add regression test

Author: OlivierBlanvillain

tests/pos/i3955.scala

@@ -0,0 +1,4 @@
+object Foo {
+  inline def f[S, T](x: S): T = ???
+  def g(x: Int) = f[T = Any](x)
+}