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

[Roland McGrath via cfe-commits]

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@@ -452,6 +454,9 @@ arm::FloatABI arm::getDefaultFloatABI(const llvm::Triple &Triple) {
   case llvm::Triple::OpenBSD:
     return FloatABI::SoftFP;
 
+  case llvm::Triple::Fuchsia:
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frobtech wrote:

Oh, I didn't realize that this "environment" was tied to the normalized triple text itself.  I agree, we want the maximal triple to be something like `armv8-unknown-fuchsia` at most and canonically would tell people to just use `--target=arm-fuchsia` for sure.  I just meant that it seemed likely that more actual choices would match what `::GNUEABIHF` is used for than not, at a guess.  (We are going for pretty much the `armv7-linux-gnueabihf` ABI in terms of _most things_: ISA support, code-gen details, C-visible core ABI issues, though armv8+... for `-march` and some differences in libc ABI expectations.)

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