Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/BinaryFormat/Dwarf.h b/linux-x64/clang/include/llvm/BinaryFormat/Dwarf.h
index 9036f40..330e31c 100644
--- a/linux-x64/clang/include/llvm/BinaryFormat/Dwarf.h
+++ b/linux-x64/clang/include/llvm/BinaryFormat/Dwarf.h
@@ -150,9 +150,8 @@
 
 enum EndianityEncoding {
   // Endianity attribute values
-  DW_END_default = 0x00,
-  DW_END_big = 0x01,
-  DW_END_little = 0x02,
+#define HANDLE_DW_END(ID, NAME) DW_END_##NAME = ID,
+#include "llvm/BinaryFormat/Dwarf.def"
   DW_END_lo_user = 0x40,
   DW_END_hi_user = 0xff
 };