[IFS] Fix the copy constructor warning in IFSStub.cpp

This change fixes the gcc warning on copy constructor in IFSStub.cpp
file.

Differential Revision: https://reviews.llvm.org/D108000

Author: zeroomega

llvm/lib/InterfaceStub/IFSStub.cpp

@@ -29,15 +29,15 @@ IFSStub::IFSStub(IFSStub &&Stub) {
   Symbols = std::move(Stub.Symbols);
 }
 
-IFSStubTriple::IFSStubTriple(IFSStubTriple const &Stub) {
+IFSStubTriple::IFSStubTriple(IFSStubTriple const &Stub) : IFSStub() {
   IfsVersion = Stub.IfsVersion;
   Target = Stub.Target;
   SoName = Stub.SoName;
   NeededLibs = Stub.NeededLibs;
   Symbols = Stub.Symbols;
 }
 
-IFSStubTriple::IFSStubTriple(IFSStub const &Stub) {
+IFSStubTriple::IFSStubTriple(IFSStub const &Stub) : IFSStub() {
   IfsVersion = Stub.IfsVersion;
   Target = Stub.Target;
   SoName = Stub.SoName;