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-h_REF.gc

@@ -3,18 +3,15 @@
 
 ;; definition of type pos-history
 (deftype pos-history (structure)
-  ((points     (inline-array vector)  :offset-assert   0)
-   (num-points int32                  :offset-assert   4)
-   (h-first    int32                  :offset-assert   8)
-   (h-last     int32                  :offset-assert  12)
+  ((points      (inline-array vector))
+   (num-points  int32)
+   (h-first     int32)
+   (h-last      int32)
    )
-  :method-count-assert 9
-  :size-assert         #x10
-  :flag-assert         #x900000010
   )
 
 ;; definition for method 3 of type pos-history
-(defmethod inspect pos-history ((this pos-history))
+(defmethod inspect ((this pos-history))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -30,18 +27,15 @@
 
 ;; definition of type debug-vertex
 (deftype debug-vertex (structure)
-  ((trans  vector4w :inline :offset-assert   0)
-   (normal vector3h :inline :offset-assert  16)
-   (st     vector2h :inline :offset-assert  22)
-   (color  uint32           :offset-assert  28)
+  ((trans   vector4w  :inline)
+   (normal  vector3h  :inline)
+   (st      vector2h  :inline)
+   (color   uint32)
    )
-  :method-count-assert 9
-  :size-assert         #x20
-  :flag-assert         #x900000020
   )
 
 ;; definition for method 3 of type debug-vertex
-(defmethod inspect debug-vertex ((this debug-vertex))
+(defmethod inspect ((this debug-vertex))
   (when (not this)
     (set! this this)
     (goto cfg-4)
@@ -57,17 +51,14 @@
 
 ;; definition of type debug-vertex-stats
 (deftype debug-vertex-stats (basic)
-  ((length    int32                    :offset-assert   4)
-   (pos-count int32                    :offset-assert   8)
-   (vertex    debug-vertex 600 :inline :offset-assert  16)
+  ((length     int32)
+   (pos-count  int32)
+   (vertex     debug-vertex  600 :inline)
    )
-  :method-count-assert 9
-  :size-assert         #x4b10
-  :flag-assert         #x900004b10
   )
 
 ;; definition for method 3 of type debug-vertex-stats
-(defmethod inspect debug-vertex-stats ((this debug-vertex-stats))
+(defmethod inspect ((this debug-vertex-stats))
   (when (not this)
     (set! this this)
     (goto cfg-4)