LICM pass stopped working

Start with the minimal TypeScript loop example and compare its unoptimized and optimized WAT output, then inspect the LICM pass and the changes referenced in #4059, #4077, and #4076. Done means the load is safely hoisted before the loop and the optimized output matches the expected WAT behavior.

After some of this changes: #4059 or #4077 or #4076

LICM pass stopped working.

Here minimal example:

export function loop1(n: i32, ptr: usize): void {
  let acc = 0;
  for (let i = 0; i < n; i++) {
    acc += load<i32>(ptr);
  }
}

Unoptimized version (original):

(module
 (type $i32_i32_=>_none (func (param i32 i32)))
 (memory $0 0)
 (export "loop1" (func $loop-test/loop1))
 (export "memory" (memory $0))
 (func $loop-test/loop1 (param $0 i32) (param $1 i32)
  (local $2 i32)
  (local $3 i32)
  (local $4 i32)
  i32.const 0
  local.set $2
  i32.const 0
  local.set $3
  loop $for-loop|0
   local.get $3
   local.get $0
   i32.lt_s
   local.set $4
   local.get $4
   if
    local.get $2
    local.get $1
    i32.load
    i32.add
    local.set $2
    local.get $3
    i32.const 1
    i32.add
    local.set $3
    br $for-loop|0
   end
  end
 )
)

Optimized:

(module
 (type $i32_i32_=>_none (func (param i32 i32)))
 (memory $0 0)
 (export "loop1" (func $loop-test/loop1))
 (export "memory" (memory $0))
 (func $loop-test/loop1 (param $0 i32) (param $1 i32)
  (local $2 i32)
  (local $3 i32)
  loop $for-loop|0
   local.get $0
   local.get $2
   i32.gt_s
   if
    local.get $1
    i32.load
    local.get $3
    i32.add
    local.set $3
    local.get $2
    i32.const 1
    i32.add
    local.set $2
    br $for-loop|0
   end
  end
 )
)

Expected:

(module
 (type $i32_i32_=>_none (func (param i32 i32)))
 (memory $0 0)
 (export "loop1" (func $module/loop1))
 (export "memory" (memory $0))
 (func $module/loop1 (param $0 i32) (param $1 i32)
  (local $2 i32)
  (local $3 i32)
  local.get $1
  i32.load
  local.set $1
  loop $for-loop|0
   local.get $0
   local.get $2
   i32.gt_s
   if
    local.get $1
    local.get $3
    i32.add
    local.set $3
    local.get $2
    i32.const 1
    i32.add
    local.set $2
    br $for-loop|0
   end
  end
 )
)