Infer u32 from 32-bit integer literals if MSB is set

tests/compiler/std/polyfills.untouched.wat

@@ -84,9 +84,7 @@
      )
      (i32.and
       (get_local $0)
-      (i32.wrap/i64
-       (i64.const 4294901760)
-      )
+      (i32.const -65536)
      )
     )
    )
@@ -224,9 +222,7 @@
      )
      (i32.and
       (get_local $0)
-      (i32.wrap/i64
-       (i64.const 4294901760)
-      )
+      (i32.const -65536)
      )
     )
    )

tests/compiler/std/symbol.optimized.wat

@@ -30,16 +30,21 @@
  (export "memory" (memory $0))
  (start $start)
  (func $~lib/symbol/Symbol#constructor (; 1 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
-  (local $2 i32)
   (set_global $~lib/symbol/nextId
    (i32.add
-    (tee_local $2
+    (tee_local $0
      (get_global $~lib/symbol/nextId)
     )
     (i32.const 1)
    )
   )
-  (get_local $2)
+  (if
+   (i32.eqz
+    (get_local $0)
+   )
+   (unreachable)
+  )
+  (get_local $0)
  )
  (func $~lib/allocator/arena/allocate_memory (; 2 ;) (type $ii) (param $0 i32) (result i32)
   (local $1 i32)
@@ -1639,6 +1644,12 @@
     (i32.const 1)
    )
   )
+  (if
+   (i32.eqz
+    (get_local $1)
+   )
+   (unreachable)
+  )
   (call $~lib/map/Map<String,usize>#set
    (get_global $~lib/symbol/stringToId)
    (get_local $0)

tests/compiler/std/symbol.untouched.wat

@@ -45,7 +45,8 @@
  (start $start)
  (func $~lib/symbol/Symbol#constructor (; 1 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (local $2 i32)
-  (return
+  (local $3 i32)
+  (set_local $3
    (block (result i32)
     (set_local $2
      (get_global $~lib/symbol/nextId)
@@ -59,6 +60,15 @@
     (get_local $2)
    )
   )
+  (if
+   (i32.eqz
+    (get_local $3)
+   )
+   (unreachable)
+  )
+  (return
+   (get_local $3)
+  )
  )
  (func $~lib/allocator/arena/allocate_memory (; 2 ;) (type $ii) (param $0 i32) (result i32)
   (local $1 i32)
@@ -1979,6 +1989,12 @@
     (get_local $1)
    )
   )
+  (if
+   (i32.eqz
+    (get_local $2)
+   )
+   (unreachable)
+  )
   (call $~lib/map/Map<String,usize>#set
    (get_global $~lib/symbol/stringToId)
    (get_local $0)