[debugger] PrepareFunctionForBreakPoints handles both fcg code and bytecode.

src/compiler.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/compiler.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "src/asmjs/asm-js.h"
@@ skipping 508 matching lines @@
 }
 
 void InstallSharedCompilationResult(CompilationInfo* info,
                                     Handle<SharedFunctionInfo> shared) {
   // TODO(mstarzinger): Compiling for debug code might be used to reveal inner
   // functions via {FindSharedFunctionInfoInScript}, in which case we end up
   // regenerating existing bytecode. Fix this!
   if (info->is_debug() && info->has_bytecode_array()) {
     shared->ClearBytecodeArray();
   }
-  // Assert that we are not overwriting (possibly patched) debug code.
-  DCHECK(!shared->HasDebugInfo());
   DCHECK(!info->code().is_null());
   shared->ReplaceCode(*info->code());
   if (info->has_bytecode_array()) {
     DCHECK(!shared->HasBytecodeArray());  // Only compiled once.
     shared->set_bytecode_array(*info->bytecode_array());
   }
 }
 
 MUST_USE_RESULT MaybeHandle<Code> GetUnoptimizedCode(CompilationInfo* info) {
   VMState<COMPILER> state(info->isolate());
@@ skipping 1414 matching lines @@
     DCHECK(shared->is_compiled());
     function->set_literals(cached.literals);
   } else if (shared->is_compiled()) {
     // TODO(mvstanton): pass pretenure flag to EnsureLiterals.
     JSFunction::EnsureLiterals(function);
   }
 }
 
 }  // namespace internal
 }  // namespace v8