[llvm] [Support] Redefine endianness::native (PR #67876)

[Jakub Kuderski via llvm-commits]

================
@@ -24,7 +24,11 @@
 namespace llvm {
 namespace support {
 
-enum endianness {big, little, native};
+enum endianness {
----------------
kuhar wrote:

Would be nice to make it `enum class` at some point

https://github.com/llvm/llvm-project/pull/67876