Disabled -Yno-double-bindings for a neg test.

The test introduced a double definition, which led to a double
binding. With -Yno-double-bindings this cauases an assertion violation
instead of a reported error.

Author: odersky

test/dotc/tests.scala

@@ -88,7 +88,7 @@ class tests extends CompilerTest {
   @Test def neg_typedapply() = compileFile(negDir, "typedapply", xerrors = 4)
   @Test def neg_typedidents() = compileFile(negDir, "typedIdents", xerrors = 2)
   @Test def neg_assignments() = compileFile(negDir, "assignments", xerrors = 3)
-  @Test def neg_typers() = compileFile(negDir, "typers", xerrors = 12)
+  @Test def neg_typers() = compileFile(negDir, "typers", xerrors = 12)(allowDoubleBindings)
   @Test def neg_privates() = compileFile(negDir, "privates", xerrors = 2)
   @Test def neg_rootImports = compileFile(negDir, "rootImplicits", xerrors = 2)
   @Test def neg_templateParents() = compileFile(negDir, "templateParents", xerrors = 3)