[MC] Fix emitCOFFSafeSEH after 9b44cfb

Tested by lld/test/COFF/safeseh*.s but not by llvm/test/**

Author: MaskRay

llvm/lib/MC/MCWinCOFFStreamer.cpp

@@ -196,7 +196,9 @@ void MCWinCOFFStreamer::emitCOFFSafeSEH(MCSymbol const *Symbol) {
   getAssembler().registerSection(*SXData);
   SXData->ensureMinAlignment(Align(4));
 
-  insert(getContext().allocFragment<MCSymbolIdFragment>(Symbol));
+  auto *F = getContext().allocFragment<MCSymbolIdFragment>(Symbol);
+  F->setParent(SXData);
+  SXData->addFragment(*F);
   getAssembler().registerSymbol(*Symbol);
   CSymbol->setIsSafeSEH();