[wasm] Remove another unnecessary undefined-instance check

src/frames.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/frames.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/base/bits.h"
@@ skipping 1511 matching lines @@
   accumulator->Add((mode == OVERVIEW) ? "%5d: " : "[%d]: ", index);
 }
 
 void WasmFrame::Print(StringStream* accumulator, PrintMode mode,
                       int index) const {
   PrintIndex(accumulator, mode, index);
   accumulator->Add("WASM [");
   Script* script = this->script();
   accumulator->PrintName(script->name());
   int pc = static_cast<int>(this->pc() - LookupCode()->instruction_start());
-  Vector<const uint8_t> raw_func_name;
-  Object* instance_or_undef = this->wasm_instance();
-  if (instance_or_undef->IsUndefined(this->isolate())) {
-    raw_func_name = STATIC_CHAR_VECTOR("<undefined>");
-  } else {
-    raw_func_name = WasmInstanceObject::cast(instance_or_undef)
-                        ->compiled_module()
-                        ->GetRawFunctionName(this->function_index());
-  }
+  Object* instance = this->wasm_instance();
+  Vector<const uint8_t> raw_func_name =
+      WasmInstanceObject::cast(instance)->compiled_module()->GetRawFunctionName(
+          this->function_index());
   const int kMaxPrintedFunctionName = 64;
   char func_name[kMaxPrintedFunctionName + 1];
   int func_name_len = std::min(kMaxPrintedFunctionName, raw_func_name.length());
   memcpy(func_name, raw_func_name.start(), func_name_len);
   func_name[func_name_len] = '\0';
   accumulator->Add("], function #%u ('%s'), pc=%p, pos=%d\n",
                    this->function_index(), func_name, pc, this->position());
   if (mode != OVERVIEW) accumulator->Add("\n");
 }
 
@@ skipping 492 matching lines @@
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 }  // namespace internal
 }  // namespace v8