Fix test

i3882.scala can be compiled only if deep subtypes are allowed.

Author: odersky

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -191,6 +191,7 @@ class CompilationTests extends ParallelTesting {
     compileFile("../tests/neg-custom-args/pureStatement.scala", defaultOptions.and("-Xfatal-warnings")) +
     compileFile("../tests/neg-custom-args/i3589-a.scala", defaultOptions.and("-Xfatal-warnings")) +
     compileFile("../tests/neg-custom-args/i2333.scala", defaultOptions.and("-Xfatal-warnings")) +
+    compileFile("../tests/neg-custom-args/i3882.scala", allowDeepSubtypes) +
     compileFile("../tests/neg-custom-args/phantom-overload.scala", allowDoubleBindings) +
     compileFile("../tests/neg-custom-args/phantom-overload-2.scala", allowDoubleBindings) +
     compileFile("../tests/neg-custom-args/structural.scala", defaultOptions.and("-Xfatal-warnings"))