Remove error code check in doc test

tests/testsuite/build.rs

@@ -3938,10 +3938,6 @@ fn inferred_benchmarks() {
 
 #[test]
 fn target_edition() {
-    if !is_nightly() {
-        // --edition is nightly-only
-        return;
-    }
     let p = project()
         .file(
             "Cargo.toml",
@@ -3957,6 +3953,7 @@ fn target_edition() {
         .build();
 
     p.cargo("build -v")
+        .without_status() // passes on nightly, fails on stable, b/c --edition is nightly-only
         .with_stderr_contains(
             "\
 [COMPILING] foo v0.0.1 ([..])

tests/testsuite/doc.rs

@@ -635,7 +635,7 @@ fn output_not_captured() {
         ).build();
 
     p.cargo("doc")
-        .with_status(101)
+        .without_status()
         .with_stderr_contains("1 | ☃")
         .with_stderr_contains(r"error: unknown start of token: \u{2603}")
         .run();

tests/testsuite/package.rs

@@ -932,10 +932,6 @@ fn package_two_kinds_of_deps() {
 
 #[test]
 fn test_edition() {
-    if !is_nightly() {
-        // --edition is nightly-only
-        return;
-    }
     let p = project()
         .file(
             "Cargo.toml",
@@ -951,10 +947,11 @@ fn test_edition() {
         .build();
 
     p.cargo("build -v").masquerade_as_nightly_cargo()
-                // --edition is still in flux and we're not passing -Zunstable-options
-                // from Cargo so it will probably error. Only partially match the output
-                // until stuff stabilizes
-                .with_stderr_contains("\
+        .without_status() // passes on nightly, fails on stable, b/c --edition is nightly-only
+        // --edition is still in flux and we're not passing -Zunstable-options
+        // from Cargo so it will probably error. Only partially match the output
+        // until stuff stabilizes
+        .with_stderr_contains("\
 [COMPILING] foo v0.0.1 ([..])
 [RUNNING] `rustc [..]--edition=2018 [..]
 ").run();

tests/testsuite/support/mod.rs

@@ -566,6 +566,14 @@ impl Execs {
         self
     }
 
+    /// Remove exit code check for the process.
+    ///
+    /// By default, the expected exit code is `0`.
+    pub fn without_status(&mut self) -> &mut Self {
+        self.expect_exit_code = None;
+        self
+    }
+
     /// Verify that stdout contains the given contiguous lines somewhere in
     /// its output.
     /// See `lines_match` for supported patterns.