Add support for Nuxi CloudABI.

CloudABI is a POSIX-like runtime environment built around the concept of
capability-based security. More details:

	https://github.com/NuxiNL/cloudlibc

CloudABI uses its own ELFOSABI number. This number has been allocated by
the maintainers of ELF a couple of days ago.

Reviewed by:	echristo


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231681 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-readobj/ELFDumper.cpp

@@ -207,6 +207,7 @@ static const EnumEntry<unsigned> ElfOSABI[] = {
   { "NSK",          ELF::ELFOSABI_NSK          },
   { "AROS",         ELF::ELFOSABI_AROS         },
   { "FenixOS",      ELF::ELFOSABI_FENIXOS      },
+  { "CloudABI",     ELF::ELFOSABI_CLOUDABI     },
   { "C6000_ELFABI", ELF::ELFOSABI_C6000_ELFABI },
   { "C6000_LINUX" , ELF::ELFOSABI_C6000_LINUX  },
   { "ARM",          ELF::ELFOSABI_ARM          },