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-focusable_REF.gc

@@ -3,26 +3,22 @@
 
 ;; definition of type process-focusable
 (deftype process-focusable (process-drawable)
-  ((root         collide-shape  :override)
-   (focus-status focus-status   :offset-assert 200)
+  ((root          collide-shape :override)
+   (focus-status  focus-status)
    )
-  :heap-base #x50
-  :method-count-assert 27
-  :size-assert         #xcc
-  :flag-assert         #x1b005000cc
   (:methods
-    (get-trans (_type_ int) vector 20)
-    (get-quat (_type_ int) quaternion 21)
-    (get-transv (_type_) vector 22)
-    (time-to-apex-or-ground (_type_ int) int 23)
-    (get-water-height (_type_) meters 24)
-    (get-notice-time (_type_) time-frame 25)
-    (get-inv-mass (_type_) float 26)
+    (get-trans (_type_ int) vector)
+    (get-quat (_type_ int) quaternion)
+    (get-transv (_type_) vector)
+    (time-to-apex-or-ground (_type_ int) int)
+    (get-water-height (_type_) meters)
+    (get-notice-time (_type_) time-frame)
+    (get-inv-mass (_type_) float)
     )
   )
 
 ;; definition for method 3 of type process-focusable
-(defmethod inspect process-focusable ((this process-focusable))
+(defmethod inspect ((this process-focusable))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -37,7 +33,7 @@
 
 ;; definition for method 20 of type process-focusable
 ;; WARN: Return type mismatch structure vs vector.
-(defmethod get-trans process-focusable ((this process-focusable) (arg0 int))
+(defmethod get-trans ((this process-focusable) (arg0 int))
   "@returns the `trans` [[vector]] from the process's `root` (typically either a [[trsqv]] or a [[collide-shape]])"
   (let ((gp-0 (-> this root)))
     (the-as vector (cond
@@ -59,34 +55,34 @@
   )
 
 ;; definition for method 22 of type process-focusable
-(defmethod get-transv process-focusable ((this process-focusable))
+(defmethod get-transv ((this process-focusable))
   (-> this root transv)
   )
 
 ;; definition for method 21 of type process-focusable
-(defmethod get-quat process-focusable ((this process-focusable) (arg0 int))
+(defmethod get-quat ((this process-focusable) (arg0 int))
   (-> this root quat)
   )
 
 ;; definition for method 23 of type process-focusable
-(defmethod time-to-apex-or-ground process-focusable ((this process-focusable) (arg0 int))
+(defmethod time-to-apex-or-ground ((this process-focusable) (arg0 int))
   0
   )
 
 ;; definition for method 24 of type process-focusable
 ;; WARN: Return type mismatch int vs meters.
-(defmethod get-water-height process-focusable ((this process-focusable))
+(defmethod get-water-height ((this process-focusable))
   (the-as meters 0)
   )
 
 ;; definition for method 26 of type process-focusable
-(defmethod get-inv-mass process-focusable ((this process-focusable))
+(defmethod get-inv-mass ((this process-focusable))
   0.0
   )
 
 ;; definition for method 25 of type process-focusable
 ;; WARN: Return type mismatch int vs time-frame.
-(defmethod get-notice-time process-focusable ((this process-focusable))
+(defmethod get-notice-time ((this process-focusable))
   (the-as time-frame 0)
   )