[wasm] Enable wasm frame inspection for debugging

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 12729 matching lines @@
            SMI_VALUE(ends->get(info->line - 1)) < position);
     info->line_start = SMI_VALUE(ends->get(info->line - 1)) + 1;
     info->column = position - info->line_start;
   }
 
   // Line end is position of the linebreak character.
   info->line_end = SMI_VALUE(ends->get(info->line));
   if (info->line_end > 0) {
     DCHECK(script->source()->IsString());
     Handle<String> src(String::cast(script->source()));
-    if (src->Get(info->line_end - 1) == '\r') {
+    if (src->length() >= info->line_end &&
+        src->Get(info->line_end - 1) == '\r') {
       info->line_end--;
     }
   }
 
   // Add offsets if requested.
   if (offset_flag == WITH_OFFSET) {
     if (info->line == 0) {
       info->column += script->column_offset();
     }
     info->line += script->line_offset();
@@ skipping 6073 matching lines @@
   } else {
     // Old-style generators.
     int offset = continuation();
     CHECK(0 <= offset && offset < function()->code()->instruction_size());
     return function()->code()->SourcePosition(offset);
   }
 }
 
 }  // namespace internal
 }  // namespace v8