Missing optimization in Wasm for `x < 0 || x > constant`

The attached .wasm file has this code at offset 95044:

 95044|        block $label3
 95046|          block $label2
 95048|            local.get $var6
 95050|            i64.const 0
 95052|            i64.lt_s                     ;; $var6 < 0 (signed)
 95053|            br_if $label2                ;; Jump to error branch
 95055|            local.get $var6
 95057|            i64.const 255
 95060|            i64.gt_s                     ;; $var6 > 255 (signed)
 95061|            i32.eqz                      ;; Negate the condition
 95062|            br_if $label3                ;; Jump to OK branch
 95064|          end $label2                    ;; Error branch
 95065|          call $FormatException
 95068|          call $Error._throwWithCurrentStackTrace
 95071|          unreachable
 95072|        end $label3                      ;; OK branch

This is a direct translation of Dart code:

if (value < 0 || value > 255) throw ...

When optimized with wasm-opt 765c61445 (current main branch) using flags

--all-features
--closed-world
--traps-never-happen
--type-unfinalizing
-Os
--type-ssa
--gufa
-Os
--type-merging
-Os
--type-finalizing

wasm-opt generates this:

local.tee $var0
i64.const 0
i64.ge_s                        ;; var0 >= 0 (signed)
local.get $var0
i64.const 255
i64.le_s                        ;; var0 =< 255 (signed)
i32.and
if                              ;; OK branch
  ...
else                            ;; Error branch
  ...
end

Here var0 >= 0 && var0 <= 255 part could be optimized to a single unsigned comparison

local.get $var0
i64.const 255
i64.le_u
if
  ...                           ;; OK branch
else
  ...                           ;; Error branch
end

Interestingly on a different program with the exact same Dart expression, wasm-opt generates different instructions, but with the same missing optimization:

local.get $var9
i64.const 0
i64.lt_s                ;; $var9 < 0 (signed)
br_if $label4
local.get $var9
i64.const 255
i64.gt_s                ;; $var9 > 255 (signed)
i32.eqz
br_if $label5

For this second program, an older wasm-opt (d844d2e77) generates code with a more obvious missing optimization:

local.tee $var5
i64.const 0
i64.ge_u                   ;; var5 >= 0 (unsigned)
local.get $var5
i64.const 255
i64.le_u                   ;; var5 <= 255 (unsigned)
i32.and
i32.eqz

Here ge_u against 0 will always evaluate to 1, so the code can be simplified to the same optimized code as above.

test.wasm.zip

Start by reproducing the attached test.wasm.zip with wasm-opt 765c61445 and the listed optimization flags, then compare the generated instructions with the expected unsigned comparison. Trace the relevant optimization passes for the signed range check and add a regression test showing that the equivalent 0–255 condition folds to one unsigned comparison.