[lldb] Remove unused method declaration

[alexander-shaposhnikov]

Summary

FindCompleteObjCDefinitionType is not used anywhere (don't confuse it with FindCompleteObjCDefinitionTypeForDIE which is called in many places, of course), and even there is no implementation of it, only a declaration, thus it can be safely removed.
Test plan: make check-lldb

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

protected:
 
   virtual lldb::TypeSP
   FindDefinitionTypeForDWARFDeclContext(const DWARFDeclContext &die_decl_ctx);
 
   lldb::TypeSP FindCompleteObjCDefinitionTypeForDIE(
       const DWARFDIE &die, const lldb_private::ConstString &type_name,
       bool must_be_implementation);
 
-  lldb::TypeSP
-  FindCompleteObjCDefinitionType(const lldb_private::ConstString &type_name,
-                                 bool header_definition_ok);
-
   lldb_private::Symbol *
   GetObjCClassSymbol(const lldb_private::ConstString &objc_class_name);
 
   void ParseFunctions(const DIEArray &die_offsets, bool include_inlines,
                       lldb_private::SymbolContextList &sc_list);
 
   lldb::TypeSP GetTypeForDIE(const DWARFDIE &die,
                              bool resolve_function_context = false);