Convert `filter` from a function to a macro

Doesn't make a big difference, just for fun. I like the idea of a
compile-time version of this since it's essentially just renaming
`remove-if-not`.

Move it to a new file so we can include it before it's used in
`main.lisp`.

1 files changed, 1 insertions, 0 deletions

diff --git a/l/extreload.asd b/l/extreload.asd
index 5edcdd7..21a5329 100644
--- a/l/extreload.asd
+++ b/l/extreload.asd
@@ -5,6 +5,7 @@
   :components ((:module "src"
                 :serial t
                 :components ((:file "package")
+                             (:file "macro")
                              (:file "main"))))
 
   :build-operation "program-op"