Windows dump_syms: Add dumping of x86_64 CFI from PDB files

src/common/windows/pdb_source_line_writer.h

Index: src/common/windows/pdb_source_line_writer.h
diff --git a/src/common/windows/pdb_source_line_writer.h b/src/common/windows/pdb_source_line_writer.h
index e9e89bb279ed25411cda60fa63a9186c978158d8..3f8d8754dc0ccea8e347ef1476703c4fda032bc4 100644
--- a/src/common/windows/pdb_source_line_writer.h
+++ b/src/common/windows/pdb_source_line_writer.h
@@ -162,6 +162,11 @@ class PDBSourceLineWriter {
   bool PrintFrameDataUsingEXE();
 
   // Outputs all of the frame information necessary to construct stack
+  // backtraces in the absence of frame pointers. For x64 data stored in
+  // the .pdb files. Returns true on success.
+  bool PrintFrameDataUsingPDBXData();
+
+  // Outputs all of the frame information necessary to construct stack
   // backtraces in the absence of frame pointers.  Returns true on success.
   bool PrintFrameData();