[wasm] Handle potentially null callee-pc

src/frames.h

 // 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.
 
 #ifndef V8_FRAMES_H_
 #define V8_FRAMES_H_
 
 #include "src/allocation.h"
 #include "src/handles.h"
 #include "src/safepoint-table.h"
@@ skipping 466 matching lines @@
 
   bool is_java_script() const {
     Type type = this->type();
     return (type == JAVA_SCRIPT) || (type == OPTIMIZED) ||
            (type == INTERPRETED) || (type == BUILTIN);
   }
 
   // Accessors.
   Address sp() const { return state_.sp; }
   Address fp() const { return state_.fp; }
-  Address callee_pc() const { return *state_.callee_pc_address; }
+  Address callee_pc() const {
+    return state_.callee_pc_address ? *state_.callee_pc_address : nullptr;
+  }
   Address caller_sp() const { return GetCallerStackPointer(); }
 
   // If this frame is optimized and was dynamically aligned return its old
   // unaligned frame pointer.  When the frame is deoptimized its FP will shift
   // up one word and become unaligned.
   Address UnpaddedFP() const;
 
   Address pc() const { return *pc_address(); }
   void set_pc(Address pc) { *pc_address() = pc; }
 
@@ skipping 868 matching lines @@
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Isolate* isolate, Zone* zone);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_FRAMES_H_