[wasm] Implement decoding of i32v values

src/wasm/wasm-module-builder.h

Index: src/wasm/wasm-module-builder.h
diff --git a/src/wasm/wasm-module-builder.h b/src/wasm/wasm-module-builder.h
index 3765cad565e62194ba92fb3f9fe9cf341ad05329..057d6102f1fa026c1364b44e65717831ae667cb5 100644
--- a/src/wasm/wasm-module-builder.h
+++ b/src/wasm/wasm-module-builder.h
@@ -49,6 +49,11 @@ class ZoneBuffer : public ZoneObject {
     LEBHelper::write_u32v(&pos_, val);
   }
 
+  void write_i32v(int32_t val) {
+    EnsureSpace(kMaxVarInt32Size);
+    LEBHelper::write_i32v(&pos_, val);
+  }
+
   void write_size(size_t val) {
     EnsureSpace(kMaxVarInt32Size);
     DCHECK_EQ(val, static_cast<uint32_t>(val));