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/process-drawable/process-taskable_REF.gc

@@ -3,7 +3,7 @@
 
 ;; definition for method 7 of type process-taskable
 ;; WARN: Return type mismatch process-focusable vs process-taskable.
-(defmethod relocate process-taskable ((this process-taskable) (arg0 int))
+(defmethod relocate ((this process-taskable) (arg0 int))
   (if (nonzero? (-> this task))
       (&+! (-> this task) arg0)
       )
@@ -34,13 +34,13 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
   )
 
 ;; definition for method 34 of type process-taskable
-(defmethod process-taskable-method-34 process-taskable ((this process-taskable))
+(defmethod process-taskable-method-34 ((this process-taskable))
   #t
   )
 
 ;; definition for method 35 of type process-taskable
 ;; WARN: Return type mismatch art-joint-anim vs art-element.
-(defmethod get-art-elem process-taskable ((this process-taskable))
+(defmethod get-art-elem ((this process-taskable))
   "Checks various things such the current actor, task status, etc to determine the right art-group data to use
 @returns the appropriate [[art-element]] for the given NPC"
   (the-as art-element (if (> (-> this skel active-channels) 0)
@@ -51,14 +51,14 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
 
 ;; definition for method 36 of type process-taskable
 ;; WARN: Return type mismatch int vs none.
-(defmethod process-taskable-method-36 process-taskable ((this process-taskable))
+(defmethod process-taskable-method-36 ((this process-taskable))
   0
   (none)
   )
 
 ;; definition for method 37 of type process-taskable
 ;; WARN: Return type mismatch object vs none.
-(defmethod process-taskable-method-37 process-taskable ((this process-taskable))
+(defmethod process-taskable-method-37 ((this process-taskable))
   (let ((v1-1 (-> this draw shadow-ctrl)))
     (cond
       ((and (-> this draw shadow)
@@ -346,7 +346,7 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
 
 ;; definition for method 31 of type process-taskable
 ;; WARN: Return type mismatch int vs none.
-(defmethod process-taskable-method-31 process-taskable ((this process-taskable))
+(defmethod process-taskable-method-31 ((this process-taskable))
   (let ((s5-0 (new 'process 'collide-shape this (collide-list-enum usually-hit-by-player))))
     (let ((s4-0 (new 'process 'collide-shape-prim-group s5-0 (the-as uint 3) 0)))
       (set! (-> s5-0 total-prims) (the-as uint 4))
@@ -387,7 +387,7 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
 
 ;; definition for method 32 of type process-taskable
 ;; WARN: Return type mismatch int vs none.
-(defmethod process-taskable-method-32 process-taskable ((this process-taskable))
+(defmethod process-taskable-method-32 ((this process-taskable))
   (logior! (-> this skel status) (joint-control-status eye-anim))
   (set! (-> this talk-message) (text-id press-triangle-to-talk))
   (set! (-> this bounce-away) #t)
@@ -420,7 +420,7 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
 
 ;; definition for method 33 of type process-taskable
 ;; WARN: Return type mismatch int vs none.
-(defmethod init-art! process-taskable ((this process-taskable))
+(defmethod init-art! ((this process-taskable))
   "@see [[initialize-skeleton]]"
   0
   (none)
@@ -428,7 +428,7 @@ Seen take in - `true-func` which takes no args TODO - seems fishy
 
 ;; definition for method 11 of type process-taskable
 ;; WARN: Return type mismatch object vs none.
-(defmethod init-from-entity! process-taskable ((this process-taskable) (arg0 entity-actor))
+(defmethod init-from-entity! ((this process-taskable) (arg0 entity-actor))
   "Typically the method that does the initial setup on the process, potentially using the [[entity-actor]] provided as part of that.
 This commonly includes things such as:
 - stack size