There is an extesnsion to support IL: IL Support
Also take a look at xacc.
Question
Is there a some IDE for editing CIL-code? I'm looking for is specific IDE with embedded compiler/decompilder, syntax highlighting, embedded documentation etc.
ildasm+Sublime+ilasm is no good for me.
Solution
There is an extesnsion to support IL: IL Support
Also take a look at xacc.
OTHER TIPS
Try SharpDevelop 3.xx (http://www.icsharpcode.net/OpenSource/SD/Download/#SharpDevelop3x), it provides syntax highlighting and automatic build, but unfortunately it doesn't decompile existing assemblies.
You may also want to try Reflector with Reflexir plugin, but it functionality is rather limited...