Initial support for emitting unwinding information in perf jitdump.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 3c5f4161fd00f8c162a8c0c21903cceeb8e9260f..456dba7fccf81fb36f879e65eb6f7818b56cade8 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1426,9 +1426,18 @@ Handle<Code> Factory::NewCode(const CodeDesc& desc,
                               bool is_debug) {
   Handle<ByteArray> reloc_info = NewByteArray(desc.reloc_size, TENURED);
 
+  bool has_unwinding_info = desc.unwinding_info != nullptr;
+  DCHECK((has_unwinding_info && desc.unwinding_info_size > 0) ||
+         (!has_unwinding_info && desc.unwinding_info_size == 0));
+
   // Compute size.
-  int body_size = RoundUp(desc.instr_size, kObjectAlignment);
-  int obj_size = Code::SizeFor(body_size);
+  int body_size = desc.instr_size;
+  int unwinding_info_size_field_size = kInt64Size;
+  if (has_unwinding_info) {
+    body_size = RoundUp(body_size, kInt64Size) + desc.unwinding_info_size +
+                unwinding_info_size_field_size;
+  }
+  int obj_size = Code::SizeFor(RoundUp(body_size, kObjectAlignment));
 
   Handle<Code> code = NewCodeRaw(obj_size, immovable);
   DCHECK(!isolate()->heap()->memory_allocator()->code_range()->valid() ||
@@ -1444,6 +1453,7 @@ Handle<Code> Factory::NewCode(const CodeDesc& desc,
   code->set_instruction_size(desc.instr_size);
   code->set_relocation_info(*reloc_info);
   code->set_flags(flags);
+  code->set_has_unwinding_info(has_unwinding_info);
   code->set_raw_kind_specific_flags1(0);
   code->set_raw_kind_specific_flags2(0);
   code->set_is_crankshafted(crankshafted);