message: Don't use deprecated rustdoc flags in tests
  In rust-lang/rust#44138 we are adding deprecations, and so it
  breaks these tests.
diff: @@ -38,14 +38,14 @@ fn rustdoc_args() {
  "#)
  .file("src/lib.rs", r#" "#);
  - assert_that(p.cargo_process("rustdoc").arg("-v").arg("--").arg("--no-defaults"),
  + assert_that(p.cargo_process("rustdoc").arg("-v").arg("--").arg("--cfg=foo"),
  execs()
  .with_status(0)
  .with_stderr(format!("\
  [DOCUMENTING] foo v0.0.1 ({url})
  [RUNNING] `rustdoc --crate-name foo src[/]lib.rs \
  -o {dir}[/]target[/]doc \
  - --no-defaults \
  + --cfg=foo \
  -L dependency={dir}[/]target[/]debug[/]deps`
  [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
  ", dir = p.root().display(), url = p.url())));
  @@ -81,7 +81,7 @@ fn rustdoc_foo_with_bar_dependency() {
  "#);
  bar.build();
  - assert_that(foo.cargo_process("rustdoc").arg("-v").arg("--").arg("--no-defaults"),
  + assert_that(foo.cargo_process("rustdoc").arg("-v").arg("--").arg("--cfg=foo"),
  execs()
  .with_status(0)
  .with_stderr(format!("\
  @@ -90,7 +90,7 @@ fn rustdoc_foo_with_bar_dependency() {
  [DOCUMENTING] foo v0.0.1 ({url})
  [RUNNING] `rustdoc --crate-name foo src[/]lib.rs \
  -o {dir}[/]target[/]doc \
  - --no-defaults \
  + --cfg=foo \
  -L dependency={dir}[/]target[/]debug[/]deps \
  --extern [..]`
  [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
  @@ -128,14 +128,14 @@ fn rustdoc_only_bar_dependency() {
  bar.build();
  assert_that(foo.cargo_process("rustdoc").arg("-v").arg("-p").arg("bar")
  - .arg("--").arg("--no-defaults"),
  + .arg("--").arg("--cfg=foo"),
  execs()
  .with_status(0)
  .with_stderr(format!("\
  [DOCUMENTING] bar v0.0.1 ([..])
  [RUNNING] `rustdoc --crate-name bar [..]bar[/]src[/]lib.rs \
  -o {dir}[/]target[/]doc \
  - --no-defaults \
  + --cfg=foo \
  -L dependency={dir}[/]target[/]debug[/]deps`
  [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
  ", dir = foo.root().display())));
  @@ -157,7 +157,7 @@ fn rustdoc_same_name_err() {
  .file("src/lib.rs", r#" "#);
  assert_that(p.cargo_process("rustdoc").arg("-v")
  - .arg("--").arg("--no-defaults"),
  + .arg("--").arg("--cfg=foo"),
  execs()
  .with_status(101)
  .with_stderr("[ERROR] cannot document a package where a library and a \
  