[WIP] ReFinalize GlobalGet in initializers after GlobalRefining

When GlobalRefining refines the type of a global, it updates the type of
corresponding GlobalGet expressions, then runs ReFinalize to propagate the
refined types. However, it only performed these updates in function bodies,
leaving stale types on GlobalGet expressions in constant initializers. This bug
was not easily caught because the validator did not check that `GlobalGet` types
actually match the types of the corresponding globals.

Fix the validator to check the types of `GlobalGet` expressions and fix
GlobalRefining to properly update constant initializers.

Fixes #6565.

src/wasm/wasm-validator.cpp

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index d44c75c..8d6fdfc 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -1013,9 +1013,12 @@
   if (!info.validateGlobally) {
     return;
   }
-  shouldBeTrue(getModule()->getGlobalOrNull(curr->name),
-               curr,
-               "global.get name must be valid");
+  auto* global = getModule()->getGlobalOrNull(curr->name);
+  if (!shouldBeTrue(global, curr, "global.get name must be valid")) {
+    return;
+  }
+  shouldBeEqual(
+    global->type, curr->type, curr, "global.get type must match global type");
 }
 
 void FunctionValidator::visitGlobalSet(GlobalSet* curr) {

test/lit/passes/global-refining.wast

diff --git a/test/lit/passes/global-refining.wast b/test/lit/passes/global-refining.wast
index 8f0b3c2..ada0b50 100644
--- a/test/lit/passes/global-refining.wast
+++ b/test/lit/passes/global-refining.wast
@@ -193,3 +193,9 @@
     (nop)
   )
 )
+
+;; We can refine globals that are used in other global initializers as well.
+(module
+  (global $refine-me (anyref) (ref.i31 (i32.const 0)))
+  (global $get (anyref) (global.get $refine-me))
+)