Regenerate the docs. (WebAssembly#407)

It appears I didn't fully regenerate the docs after merging WebAssembly#235. This
runs the tools/repo_docs.sh script to regenerate them.

phases/ephemeral/docs.md

@@ -1098,12 +1098,17 @@ The type of the event to which to subscribe, and the contents of the subscriptio
 
 Offset: 8
 
-## <a href="#exitcode" name="exitcode"></a> `exitcode`: `u32`
-Exit code generated by a process when exiting.
+## <a href="#exitcode" name="exitcode"></a> `exitcode`: `u8`
+Exit code generated by a program when exiting.
 
-Size: 4
+Size: 1
 
-Alignment: 4
+Alignment: 1
+
+### Constants
+- <a href="#exitcode.success" name="exitcode.success"></a> `success`
+
+- <a href="#exitcode.failure" name="exitcode.failure"></a> `failure`
 
 ## <a href="#riflags" name="riflags"></a> `riflags`: `Record`
 Flags provided to `sock_recv`.