[aarch64][globalisel] Fix a crash in selectAddrModeIndexed() caused by...

[aarch64][globalisel] Fix a crash in selectAddrModeIndexed() caused by incorrect G_FRAME_INDEX handling

The wrong operand was being rendered to the result instruction.

The crash was detected by Bitcode/simd_ops/AArch64_halide_runtime.bc

llvm-svn: 315890