[gdb/symtab] C++-ify call_site

- add constructor
- add member function call_site::pc ()

Tested on x86_64-linux.

Co-Authored-By: Tom de Vries <tdevries@suse.de>

gdb/gdbtypes.c

@@ -37,6 +37,7 @@
 #include "cp-support.h"
 #include "bcache.h"
 #include "dwarf2/loc.h"
+#include "dwarf2/read.h"
 #include "gdbcore.h"
 #include "floatformat.h"
 #include "f-lang.h"
@@ -6308,6 +6309,14 @@ objfile_type (struct objfile *objfile)
   return objfile_type;
 }
 
+/* See gdbtypes.h.  */
+
+CORE_ADDR
+call_site::pc () const
+{
+  return m_pc;
+}
+
 void _initialize_gdbtypes ();
 void
 _initialize_gdbtypes ()