Precompute bug

[tlively]

;; test.wast
(module
 (type $0 (sub (array nullexternref)))
 (rec
  (type $1 (sub (struct (field f32) (field (mut (ref null $2))) (field (mut i32)) (field exnref) (field i64) (field (mut i8)))))
  (type $2 (sub (func (result i32))))
  (type $3 (sub final $0 (array nullexternref)))
 )
 (type $4 (sub (struct (field i31ref) (field (ref null $3)))))
 (type $5 (sub $2 (func (result i32))))
 (type $13 (func (result (ref null $4))))
 (type $33 (func (param anyref) (result f32)))
 (type $6 (func))
 (elem declare func $0)
 (export "func_130_invoker" (func $124))
 (func $0 (type $5) (result i32)
  (unreachable)
 )
 (func $9 (type $13) (result (ref null $4))
  (unreachable)
 )
 (func $123 (type $33) (param $0 anyref) (result f32)
  (local $2 f32)
  (drop
   (array.new_default $3
    (select
     (i32.const 0)
     (i32.const 0)
     (struct.get_u $1 5
      (struct.new $1
       (f32.const 0)
       (ref.func $0)
       (ref.eq
        (struct.new_default $4)
        (call $9)
       )
       (ref.null noexn)
       (i64.const 0)
       (i32.const 0)
      )
     )
    )
   )
  )
  (local.get $2)
 )
 (func $124 (type $6)
  (drop
   (call $123
    (ref.null none)
   )
  )
 )
)

wasm-opt -all test.wast --fuzz-exec --optimize-level=3 --precompute-propagate

The fuzz-exec results are changed after optimization.

[kripken]

Good timing, I just finished debugging that locally and opened #7766