[MachO] Use setter for globalsAreDeadStripRoots. NFC intended.

llvm-svn: 231629
diff --git a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
index b004380..e68d1da 100644
--- a/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachOLinkingContext.cpp
@@ -214,7 +214,7 @@
     }
     break;
   case llvm::MachO::MH_DYLIB:
-    _globalsAreDeadStripRoots = true;
+    setGlobalsAreDeadStripRoots(true);
     break;
   case llvm::MachO::MH_BUNDLE:
     break;
@@ -570,7 +570,7 @@
       addDeadStripRoot(binderSymbolName());
     // If using -exported_symbols_list, make all exported symbols live.
     if (_exportMode == ExportMode::whiteList) {
-      _globalsAreDeadStripRoots = false;
+      setGlobalsAreDeadStripRoots(false);
       for (const auto &symbol : _exportedSymbols)
         addDeadStripRoot(symbol.getKey());
     }