[embind] Honor SUPPORTS_GLOBALTHIS. NFC (#24474)

Author: sbc100

src/lib/libemval.js

@@ -141,7 +141,9 @@ var LibraryEmVal = {
     return Emval.toHandle(v);
   },
 
-#if !DYNAMIC_EXECUTION
+#if SUPPORTS_GLOBALTHIS
+  $emval_get_global: () => globalThis,
+#elif !DYNAMIC_EXECUTION
   $emval_get_global: () => {
     if (typeof globalThis == 'object') {
       return globalThis;

test/code_size/embind_val_wasm.json

@@ -1,10 +1,10 @@
 {
   "a.html": 552,
   "a.html.gz": 380,
-  "a.js": 6463,
-  "a.js.gz": 2798,
+  "a.js": 5971,
+  "a.js.gz": 2670,
   "a.wasm": 9083,
   "a.wasm.gz": 4682,
-  "total": 16098,
-  "total_gz": 7860
+  "total": 15606,
+  "total_gz": 7732
 }