deftype and defmethod syntax major changes (#3094)

Major change to how `deftype` shows up in our code:
- the decompiler will no longer emit the `offset-assert`,
`method-count-assert`, `size-assert` and `flag-assert` parameters. There
are extremely few cases where having this in the decompiled code is
helpful, as the types there come from `all-types` which already has
those parameters. This also doesn't break type consistency because:
  - the asserts aren't compared.
- the first step of the test uses `all-types`, which has the asserts,
which will throw an error if they're bad.
- the decompiler won't emit the `heap-base` parameter unless necessary
now.
- the decompiler will try its hardest to turn a fixed-offset field into
an `overlay-at` field. It falls back to the old offset if all else
fails.
- `overlay-at` now supports field "dereferencing" to specify the offset
that's within a field that's a structure, e.g.:
```lisp
(deftype foobar (structure)
  ((vec    vector  :inline)
   (flags  int32   :overlay-at (-> vec w))
   )
  )
```
in this structure, the offset of `flags` will be 12 because that is the
final offset of `vec`'s `w` field within this structure.
- **removed ID from all method declarations.** IDs are only ever
automatically assigned now. Fixes #3068.
- added an `:overlay` parameter to method declarations, in order to
declare a new method that goes on top of a previously-defined method.
Syntax is `:overlay <method-name>`. Please do not ever use this.
- added `state-methods` list parameter. This lets you quickly specify a
list of states to be put in the method table. Same syntax as the
`states` list parameter. The decompiler will try to put as many states
in this as it can without messing with the method ID order.

Also changes `defmethod` to make the first type definition (before the
arguments) optional. The type can now be inferred from the first
argument. Fixes #3093.

---------

Co-authored-by: Hat Kid <6624576+Hat-Kid@users.noreply.github.com>

test/decompiler/reference/jak2/engine/debug/debug_REF.gc

@@ -447,21 +447,18 @@
 (when *debug-segment*
 ;; definition of type debug-line
 (deftype debug-line (structure)
-  ((flags  int32             :offset-assert   0)
-   (bucket bucket-id         :offset-assert   4)
-   (v1     vector    :inline :offset-assert  16)
-   (v2     vector    :inline :offset-assert  32)
-   (color  rgba              :offset-assert  48)
-   (mode   symbol            :offset-assert  52)
-   (color2 rgba              :offset-assert  56)
+  ((flags   int32)
+   (bucket  bucket-id)
+   (v1      vector  :inline)
+   (v2      vector  :inline)
+   (color   rgba)
+   (mode    symbol)
+   (color2  rgba)
    )
-  :method-count-assert 9
-  :size-assert         #x3c
-  :flag-assert         #x90000003c
   )
 
 ;; definition for method 3 of type debug-line
-(defmethod inspect debug-line ((this debug-line))
+(defmethod inspect ((this debug-line))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -480,20 +477,17 @@
 
 ;; definition of type debug-text-3d
 (deftype debug-text-3d (structure)
-  ((flags  int32              :offset-assert   0)
-   (bucket bucket-id          :offset-assert   4)
-   (pos    vector     :inline :offset-assert  16)
-   (color  font-color         :offset-assert  32)
-   (offset vector2h   :inline :offset-assert  36)
-   (str    string             :offset-assert  40)
+  ((flags   int32)
+   (bucket  bucket-id)
+   (pos     vector    :inline)
+   (color   font-color)
+   (offset  vector2h  :inline)
+   (str     string)
    )
-  :method-count-assert 9
-  :size-assert         #x2c
-  :flag-assert         #x90000002c
   )
 
 ;; definition for method 3 of type debug-text-3d
-(defmethod inspect debug-text-3d ((this debug-text-3d))
+(defmethod inspect ((this debug-text-3d))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -511,16 +505,13 @@
 
 ;; definition of type debug-tracking-thang
 (deftype debug-tracking-thang (basic)
-  ((length           int32  :offset-assert   4)
-   (allocated-length int32  :offset-assert   8)
+  ((length            int32)
+   (allocated-length  int32)
    )
-  :method-count-assert 9
-  :size-assert         #xc
-  :flag-assert         #x90000000c
   )
 
 ;; definition for method 3 of type debug-tracking-thang
-(defmethod inspect debug-tracking-thang ((this debug-tracking-thang))
+(defmethod inspect ((this debug-tracking-thang))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -1605,7 +1596,7 @@
   )
 
 ;; definition for method 3 of type debug-vertex-stats
-(defmethod inspect debug-vertex-stats ((this debug-vertex-stats))
+(defmethod inspect ((this debug-vertex-stats))
   (format #t "[~8x] ~A~%" this (-> this type))
   (format #t "~Tlength: ~D~%" (-> this length))
   (format #t "~Tpos-count: ~D~%" (-> this pos-count))