[wasm] GC should ignore unboxed stack parameters in WASM frames.

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 <sstream>
 
 #include "src/ast/ast.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 725 matching lines @@
     }
     // Skip the words containing the register values.
     parameters_base += kNumSafepointRegisters;
   }
 
   // We're done dealing with the register bits.
   uint8_t* safepoint_bits = safepoint_entry.bits();
   safepoint_bits += kNumSafepointRegisters >> kBitsPerByteLog2;
 
   // Visit the rest of the parameters.
-  v->VisitPointers(parameters_base, parameters_limit);
+  if (!is_js_to_wasm() && !is_wasm()) {
+    // Non-WASM frames have tagged values as parameters.
+    v->VisitPointers(parameters_base, parameters_limit);
+  }
 
   // Visit pointer spill slots and locals.
   for (unsigned index = 0; index < stack_slots; index++) {
     int byte_index = index >> kBitsPerByteLog2;
     int bit_index = index & (kBitsPerByte - 1);
     if ((safepoint_bits[byte_index] & (1U << bit_index)) != 0) {
       v->VisitPointer(parameters_limit + index);
     }
   }
 
@@ skipping 955 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