[llvm] [APFloat][NFCI] Move x87DoubleExtended next to the other native IEEE types (PR #223193)

[Eric Ross via llvm-commits]

================
@@ -3735,10 +3739,7 @@ APInt IEEEFloat::bitcastToAPInt() const {
   if (semantics == (const llvm::fltSemantics *)&APFloatBase::semFloat4E2M1FN)
     return convertFloat4E2M1FNAPFloatToAPInt();
 
-  assert(semantics ==
-             (const llvm::fltSemantics *)&APFloatBase::semX87DoubleExtended &&
-         "unknown format!");
-  return convertF80LongDoubleAPFloatToAPInt();
+  llvm_unreachable("unknown format!");
----------------
ZERICO2005 wrote:

Note: Turned `assert` into `llvm_unreachable` here.

https://github.com/llvm/llvm-project/pull/223193