Fix test expectation for aarch64 in several test case

These test cases check if they are able to read registers after the
inferior is crashed. Previously they did it with reading the eax
register what is only available on i386 and x86_64. Thic CL add code to
do the check based on the target architecture (currently i386, x86_64
and aarch64 is supported)

Differential revision: http://reviews.llvm.org/D8702

llvm-svn: 233907