Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/MC/MCELFObjectWriter.h b/linux-x64/clang/include/llvm/MC/MCELFObjectWriter.h
index 389a4d7..f226d6a 100644
--- a/linux-x64/clang/include/llvm/MC/MCELFObjectWriter.h
+++ b/linux-x64/clang/include/llvm/MC/MCELFObjectWriter.h
@@ -74,6 +74,8 @@
     switch (OSType) {
       case Triple::CloudABI:
         return ELF::ELFOSABI_CLOUDABI;
+      case Triple::HermitCore:
+        return ELF::ELFOSABI_STANDALONE;
       case Triple::PS4:
       case Triple::FreeBSD:
         return ELF::ELFOSABI_FREEBSD;