get rid of memory.cc/.hh

also fix bus' shared pointer in cpu
TODO: put cpu in bus not the other way around

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

include/meson.build

@@ -1,5 +1,4 @@
 headers = files(
-  'memory.hh',
   'bus.hh',
   'header.hh',
 )
@@ -10,4 +9,4 @@ subdir('cpu')
 subdir('util')
 subdir('io')
 
-install_headers(headers, subdir: meson.project_name(), preserve_path: true)
+install_headers(headers, subdir: meson.project_name(), preserve_path: true)