Implement MachOObjectFile::getHeaderSize directly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178995 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 31e8be0..ee42bc8 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -86,7 +86,7 @@
 }
 
 unsigned MachOObjectFile::getHeaderSize() const {
-  return MachOObj->getHeaderSize();
+  return is64Bit() ? macho::Header64Size : macho::Header32Size;
 }
 
 StringRef MachOObjectFile::getData(size_t Offset, size_t Size) const {