Stabilize --emit rustdoc command line option

Author: GuillaumeGomez

src/librustdoc/lib.rs

@@ -532,14 +532,6 @@ fn opts() -> Vec<RustcOptGroup> {
             "Generate JSON file at the top level instead of generating HTML redirection files",
             "",
         ),
-        opt(
-            Unstable,
-            Multi,
-            "",
-            "emit",
-            "Comma separated list of types of output for rustdoc to emit",
-            "[toolchain-shared-resources,invocation-specific,dep-info]",
-        ),
         opt(Unstable, FlagMulti, "", "no-run", "Compile doctests without running them", ""),
         opt(
             Unstable,
@@ -692,6 +684,14 @@ fn opts() -> Vec<RustcOptGroup> {
             "Includes trait implementations and other crate info from provided path. Only use with --merge=finalize",
             "path/to/doc.parts/<crate-name>",
         ),
+        opt(
+            Stable,
+            Multi,
+            "",
+            "emit",
+            "Comma separated list of types of output for rustdoc to emit",
+            "[toolchain-shared-resources,invocation-specific,dep-info]",
+        ),
     ]
 }