[cleanup] Remove unused own_buffer_ field in RegExpBytecodeGenerator

We don't use this anywhere, it's always true.

Change-Id: Iae16a108f036de5eddd1b9741e554ddd4eac8c83
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1692928
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62628}

src/regexp/regexp-bytecode-generator.cc

@@ -17,13 +17,12 @@ RegExpBytecodeGenerator::RegExpBytecodeGenerator(Isolate* isolate, Zone* zone)
     : RegExpMacroAssembler(isolate, zone),
       buffer_(Vector<byte>::New(1024)),
       pc_(0),
-      own_buffer_(true),
       advance_current_end_(kInvalidPC),
       isolate_(isolate) {}
 
 RegExpBytecodeGenerator::~RegExpBytecodeGenerator() {
   if (backtrack_.is_linked()) backtrack_.Unuse();
-  if (own_buffer_) buffer_.Dispose();
+  buffer_.Dispose();
 }
 
 RegExpBytecodeGenerator::IrregexpImplementation
@@ -369,14 +368,10 @@ void RegExpBytecodeGenerator::Copy(byte* a) {
 }
 
 void RegExpBytecodeGenerator::Expand() {
-  bool old_buffer_was_our_own = own_buffer_;
   Vector<byte> old_buffer = buffer_;
   buffer_ = Vector<byte>::New(old_buffer.length() * 2);
-  own_buffer_ = true;
   MemCopy(buffer_.begin(), old_buffer.begin(), old_buffer.length());
-  if (old_buffer_was_our_own) {
   old_buffer.Dispose();
-  }
 }
 
 }  // namespace internal

src/regexp/regexp-bytecode-generator.h

@@ -94,8 +94,6 @@ class V8_EXPORT_PRIVATE RegExpBytecodeGenerator : public RegExpMacroAssembler {
   Vector<byte> buffer_;
   // The program counter.
   int pc_;
-  // True if the assembler owns the buffer, false if buffer is external.
-  bool own_buffer_;
   Label backtrack_;
 
   int advance_current_start_;