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/ps2/timer_REF.gc

@@ -138,7 +138,7 @@
   )
 
 ;; definition for method 9 of type clock
-(defmethod update-rates! clock ((this clock) (arg0 float))
+(defmethod update-rates! ((this clock) (arg0 float))
   (set! (-> this clock-ratio) arg0)
   (let ((f0-6 (if (nonzero? *display*)
                   (* (-> *display* time-factor) (-> *display* dog-ratio) arg0)
@@ -164,7 +164,7 @@
   )
 
 ;; definition for method 10 of type clock
-(defmethod advance-by! clock ((this clock) (arg0 float))
+(defmethod advance-by! ((this clock) (arg0 float))
   (the int (+ arg0 (-> this accum)))
   (+! (-> this integral-accum) arg0)
   (set! (-> this old-integral-frame-counter) (-> this integral-frame-counter))
@@ -182,7 +182,7 @@
   )
 
 ;; definition for method 11 of type clock
-(defmethod tick! clock ((this clock))
+(defmethod tick! ((this clock))
   (if (not (logtest? (-> this mask) (-> *kernel-context* prevent-from-run)))
       (advance-by! this (* (-> *display* time-factor) (-> *display* dog-ratio) (-> this clock-ratio)))
       (set! (-> this sparticle-data x) 0.0)
@@ -192,7 +192,7 @@
 
 ;; definition for method 14 of type clock
 ;; WARN: Return type mismatch int vs none.
-(defmethod reset! clock ((this clock))
+(defmethod reset! ((this clock))
   (set! (-> this frame-counter) (seconds 1000))
   (set! (-> this integral-frame-counter) (the-as uint #x493e0))
   (set! (-> this accum) 0.0)
@@ -204,14 +204,14 @@
   )
 
 ;; definition for method 12 of type clock
-(defmethod save! clock ((this clock) (arg0 (pointer uint64)))
+(defmethod save! ((this clock) (arg0 (pointer uint64)))
   (set! (-> arg0 0) (the-as uint (-> this frame-counter)))
   (set! (-> arg0 1) (-> this integral-frame-counter))
   16
   )
 
 ;; definition for method 13 of type clock
-(defmethod load! clock ((this clock) (arg0 (pointer uint64)))
+(defmethod load! ((this clock) (arg0 (pointer uint64)))
   (set! (-> this frame-counter) (the-as time-frame (-> arg0 0)))
   (set! (-> this integral-frame-counter) (-> arg0 1))
   (set! (-> this accum) 0.0)