[wasm] Allocate a single script per wasm module

src/messages.h

Index: src/messages.h
diff --git a/src/messages.h b/src/messages.h
index 3a03de9ce2a2eb76c666736bbd044cbc34944625..86cc8d0dff3e44100dc0e953b1ca51d7b3180464 100644
--- a/src/messages.h
+++ b/src/messages.h
@@ -153,6 +153,7 @@ class WasmStackFrame : public StackFrameBase {
 
   Isolate* isolate_;
 
+  // TODO(wasm): Use proper typing.
   Handle<Object> wasm_instance_;
   uint32_t wasm_func_index_;
   Handle<AbstractCode> code_;
@@ -172,7 +173,6 @@ class AsmJsWasmStackFrame : public WasmStackFrame {
   Handle<Object> GetFunction() const override;
 
   Handle<Object> GetFileName() override;
-  Handle<Object> GetFunctionName() override;
   Handle<Object> GetScriptNameOrSourceUrl() override;
 
   int GetPosition() const override;