COFF: Add /failifmismatch option.

llvm-svn: 239073
diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
index 66ffa65..a49906c 100644
--- a/lld/COFF/Config.h
+++ b/lld/COFF/Config.h
@@ -13,6 +13,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Object/COFF.h"
 #include <cstdint>
+#include <map>
 #include <set>
 #include <string>
 
@@ -35,6 +36,9 @@
   std::set<StringRef> NoDefaultLibs;
   bool NoDefaultLibAll = false;
 
+  // Used by /failifmismatch option.
+  std::map<StringRef, StringRef> MustMatch;
+
   uint64_t ImageBase = 0x140000000;
   uint64_t StackReserve = 1024 * 1024;
   uint64_t StackCommit = 4096;