ARM: change attribute tests to use parsed form

This makes the tests more readable by using the -arm-attributes decoding support
in llvm-readobj since that is now available.  Change the invocation commands to
be similar to other test and use a more precise triple (the tests only require
ARM EABI support).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201029 91177308-0d34-0410-b5e6-96231b3b80d8
28 files changed