ELF: Add support for the exclude section bit for gas compat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190769 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/ELFYAML.cpp b/lib/Object/ELFYAML.cpp
index e530d3d..2f35cf9 100644
--- a/lib/Object/ELFYAML.cpp
+++ b/lib/Object/ELFYAML.cpp
@@ -266,6 +266,7 @@
 #define BCase(X) IO.bitSetCase(Value, #X, ELF::X);
   BCase(SHF_WRITE)
   BCase(SHF_ALLOC)
+  BCase(SHF_EXCLUDE)
   BCase(SHF_EXECINSTR)
   BCase(SHF_MERGE)
   BCase(SHF_STRINGS)