[AArch64] Remove unused references to MVT::f80. (#169545)

These f80 fp types are only supported on X86 and can be removed from AArch64. It looks like they were copied from another backend by mistake.

Author: davemgreen

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -530,7 +530,6 @@ AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
 
  setOperationAction(ISD::FREM, MVT::f32, Expand);
  setOperationAction(ISD::FREM, MVT::f64, Expand);
- setOperationAction(ISD::FREM, MVT::f80, Expand);
 
  setOperationAction(ISD::BUILD_PAIR, MVT::i64, Expand);