ARM: Remove redundant or buggy config of __aeabi_d2h (#152126)

This was set if `TT.isTargetAEABI()`. This was previously set above
if `TM.isAAPCS_ABI() && (TT.isTargetAEABI() || TT.isTargetGNUAEABI() ||
                         TT.isTargetMuslAEABI() || TT.isAndroid())`.

So this could differ based on a manually specified -target-abi flag due
to the `isAAPCS_ABI` part of the original condition. I'm guessing
these should be consistent, so either this second group of
setLibcallImpl
calls should have been guarded by the `isAAPCS_ABI` check, or the first
condition should remove it.

There doesn't appear to be any meaningful test coverage using the
manually specified ABI option, so #152108 tries to remove it

Author: arsenm

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -737,7 +737,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM_,
       const RTLIB::LibcallImpl Impl;
     } LibraryCalls[] = {
         {RTLIB::FPROUND_F32_F16, RTLIB::__aeabi_f2h},
-        {RTLIB::FPROUND_F64_F16, RTLIB::__aeabi_d2h},
         {RTLIB::FPEXT_F16_F32, RTLIB::__aeabi_h2f},
     };