Navigating to the definitions of `defun` and `defmacro` with slime/swank

[John DeBord]

1.
I want to navigate to the definition of `defmacro`, `defun`, etc. so that I can understand how they work. But, as it stands, I'm unable to do so.

1.
Emacs version: 26.3
Slime version: 2.26.1

I start up Emacs.

I open up a simple .lisp file
```lisp
(defun testfn (x y)
  (+ x y))

(defmacro testmc (form)
  form
  `(list 1 2 3))
```

I place my cursor over the symbol `defun` and issue the keyboard-command <M-.> (`slime-edit-definition`).

This should bring me to the definition of `defun`.

But it doesn't (shown in screenshot `sc.png` (left screenshot)).

I place my cursor over the symbol `defmacro` and issue the keyboard-command <M-.> (`slime-edit-definition`).

This should bring me to the definition of `defmacro`.

But it doesn't (shown in screenshot `sc.png` (right screenshot)).

Why does the implementation do this? And can we fix this?

2.
```sh
<user>@<host>:~$ sbcl --version
SBCL 2.0.1.debian
```

3.
```sh
<user>@<host>:~$ uname -a
Linux <host> 5.4.0-88-generic #99-Ubuntu SMP Thu Sep 23 17:29:00 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
```

4.
```sh
CL-USER> *FEATURES*
(:SWANK :QUICKLISP :SB-BSD-SOCKETS-ADDRINFO :ASDF3.3 :ASDF3.2 :ASDF3.1 :ASDF3
 :ASDF2 :ASDF :OS-UNIX :NON-BASE-CHARS-EXIST-P :ASDF-UNICODE :X86-64 :64-BIT
 :ANSI-CL :COMMON-LISP :ELF :GENCGC :IEEE-FLOATING-POINT :LINUX :LITTLE-ENDIAN
 :PACKAGE-LOCAL-NICKNAMES :SB-CORE-COMPRESSION :SB-LDB :SB-PACKAGE-LOCKS
 :SB-THREAD :SB-UNICODE :SBCL :UNIX)
```

This bug is further expounded upon at https://stackoverflow.com/questions/69686284/navigating-to-the-definitions-of-defun-and-defmacro-with-slime-swank