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/jak1/engine/debug/assert-h_REF.gc

@@ -3,21 +3,18 @@
 
 ;; definition of type __assert-info-private-struct
 (deftype __assert-info-private-struct (structure)
-  ((filename   string  :offset-assert   0)
-   (line-num   uint16  :offset-assert   4)
-   (column-num uint16  :offset-assert   6)
+  ((filename    string)
+   (line-num    uint16)
+   (column-num  uint16)
    )
-  :method-count-assert 11
-  :size-assert         #x8
-  :flag-assert         #xb00000008
   (:methods
-    (set-pos (_type_ string uint uint) int 9)
-    (print-pos (_type_) int 10)
+    (set-pos (_type_ string uint uint) int)
+    (print-pos (_type_) int)
     )
   )
 
 ;; definition for method 3 of type __assert-info-private-struct
-(defmethod inspect __assert-info-private-struct ((this __assert-info-private-struct))
+(defmethod inspect ((this __assert-info-private-struct))
   (format #t "[~8x] ~A~%" this '__assert-info-private-struct)
   (format #t "~Tfilename: ~A~%" (-> this filename))
   (format #t "~Tline-num: ~D~%" (-> this line-num))
@@ -26,7 +23,7 @@
   )
 
 ;; definition for method 9 of type __assert-info-private-struct
-(defmethod set-pos __assert-info-private-struct ((this __assert-info-private-struct) (filename string) (line-num uint) (column-num uint))
+(defmethod set-pos ((this __assert-info-private-struct) (filename string) (line-num uint) (column-num uint))
   (set! (-> this filename) filename)
   (set! (-> this line-num) line-num)
   (set! (-> this column-num) column-num)
@@ -34,7 +31,7 @@
   )
 
 ;; definition for method 10 of type __assert-info-private-struct
-(defmethod print-pos __assert-info-private-struct ((this __assert-info-private-struct))
+(defmethod print-pos ((this __assert-info-private-struct))
   (format #t "file ~S.gc, line ~D, col ~D.~%" (-> this filename) (-> this line-num) (-> this column-num))
   0
   )