Allowing optional build of a WASM prototype behind a gyp define.

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index d1eb9592777b3cfe2270df001c36db49885447c5..9531e24a44e62fc472011f0f15e1f461fd0fbcfa 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -49,6 +49,10 @@
 #include "src/v8.h"
 #endif  // !V8_SHARED
 
+#if defined(V8_WASM)
+#include "src/wasm/wasm-js.h"
+#endif
+
 #if !defined(_WIN32) && !defined(_WIN64)
 #include <unistd.h>  // NOLINT
 #else
@@ -1170,6 +1174,11 @@ Local<ObjectTemplate> Shell::CreateGlobalTemplate(Isolate* isolate) {
           .ToLocalChecked(),
       os_templ);
 
+#if defined(V8_WASM)
+  // Install WASM API.
+  WasmJs::Install(isolate, global_template);
+#endif
+
   return global_template;
 }