Add LLVM datalayout for Darwin/ARM
The DTK machine reports a triple of arm-apple-darwin20.0.0
.
The datalayout is e-m:o-p:32:32-Fi8-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32", "arm7tdmi", "+soft-float -fp16 -vfp2 -vfp2sp -vfp3 -vfp3sp -vfp3d16 -vfp3d16sp -vfp4 -vfp4sp -vfp4d16 -vfp4d16sp -fp-armv8 -fp-armv8sp -fp-armv8d16 -fp-armv8d16sp -fullfp16 -neon -crypto -dotprod -fp16fml -mve -mve.fp -fp64 -d32 -fpregs +strict-align