XXX SymbolUnion

Index: lld/ELF/Symbols.cpp
--- lld/ELF/Symbols.cpp.orig
+++ lld/ELF/Symbols.cpp
@@ -25,7 +25,7 @@ using namespace llvm::ELF;
 using namespace lld;
 using namespace lld::elf;
 
-static_assert(sizeof(SymbolUnion) <= 64, "SymbolUnion too large");
+static_assert(sizeof(SymbolUnion) <= 72, "SymbolUnion too large");
 
 template <typename T> struct AssertSymbol {
   static_assert(std::is_trivially_destructible<T>(),
@@ -59,6 +59,7 @@ std::string lld::toString(const elf::Symbol &sym) {
 }
 
 Defined *ElfSym::bss;
+Defined *ElfSym::data;
 Defined *ElfSym::etext1;
 Defined *ElfSym::etext2;
 Defined *ElfSym::edata1;