Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/Bitcode/LLVMBitCodes.h b/linux-x64/clang/include/llvm/Bitcode/LLVMBitCodes.h
index 6723cf4..5467ecc 100644
--- a/linux-x64/clang/include/llvm/Bitcode/LLVMBitCodes.h
+++ b/linux-x64/clang/include/llvm/Bitcode/LLVMBitCodes.h
@@ -591,6 +591,7 @@
   ATTR_KIND_NOCF_CHECK = 56,
   ATTR_KIND_OPT_FOR_FUZZING = 57,
   ATTR_KIND_SHADOWCALLSTACK = 58,
+  ATTR_KIND_SPECULATIVE_LOAD_HARDENING = 59,
 };
 
 enum ComdatSelectionKindCodes {