[ARM GlobalISel] Remove duplicate test. NFCI

Fixup for r349026. I forgot to delete these test functions from the
original file when I moved them to arm-legalize-exts.mir.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349146 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed