SI-8024 Fix inaccurate message on overloaded ambiguous ident

`Symbol#owner` of an overloaded symbol doesn't necessarily correspond
to the owner of any of the alternatives, and as such it shouldn't
be used in error message.

neg/t8024.scala actually represents a progression since 2.10.3;
the ambiguity was not reported. I bisected the change to
https://github.com/scala/scala/pull/1554.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/files/neg/t8024b.scala b/test/files/neg/t8024b.scala
new file mode 100644
index 0000000000..cf3d496365
--- /dev/null
+++ b/test/files/neg/t8024b.scala
@@ -0,0 +1,17 @@
+package p
+
+trait NRoot[A]
+
+object FastComplex {
+  final def sqrt(x: Double): Double = Math.sqrt(x)
+  final def sqrt[A](a: A)(implicit ev: NRoot[A]): A = ???
+
+  object Inner {
+    import java.lang.Math.sqrt
+
+    // wrong message:
+    // error: reference to sqrt is ambiguous;
+    //        it is both defined in object FastComplex and imported subsequently by
+    sqrt(0d)
+  }
+}