[yaml2obj] - Add a support for changing EntSize.

I was trying to add a test case for LLD and found that it
is impossible to set sh_entsize via yaml.
The patch implements the missing part.

Differential revision: https://reviews.llvm.org/D50235

llvm-svn: 339113
diff --git a/llvm/lib/ObjectYAML/ELFYAML.cpp b/llvm/lib/ObjectYAML/ELFYAML.cpp
index f916b5d..a381a63 100644
--- a/llvm/lib/ObjectYAML/ELFYAML.cpp
+++ b/llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -816,6 +816,7 @@
   IO.mapOptional("Address", Section.Address, Hex64(0));
   IO.mapOptional("Link", Section.Link, StringRef());
   IO.mapOptional("AddressAlign", Section.AddressAlign, Hex64(0));
+  IO.mapOptional("EntSize", Section.EntSize);
   IO.mapOptional("Info", Section.Info, StringRef());
 }