[clang] [llvm] [Clang][LLVM] Support for Fuchsia on ARM (PR #163848)

[Roland McGrath via cfe-commits]

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@@ -332,7 +333,7 @@ ARMTargetInfo::ARMTargetInfo(const llvm::Triple &Triple,
     default:
       if (IsNetBSD)
         setABI("apcs-gnu");
-      else if (IsFreeBSD || IsOpenBSD || IsHaiku || IsOHOS)
+      else if (IsFreeBSD || IsFuchsia || IsOpenBSD || IsHaiku || IsOHOS)
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frobtech wrote:

Ah right, that is the default for `-fshort-enum` IOW. I don't know why Linux long ago diverged from the clearly-published AAPCS on this, but for us matching Linux ABIs for this sort of detail (things likely relevant to porting code from arm-linux distinct from direct OS dependencies) is more important than published standards or CPU vendor's recommendations.  It would be nice if the code made it easier to discover that `aapcs-linux` means `aapcs` + `-fshort-enum`.

https://github.com/llvm/llvm-project/pull/163848