Add support for ARM and ARM64 breakpad generated minidump files

In this patch I add support for ARM and ARM64 break pad files. There are two flavors of ARM: Apple where FP is R7, and non Apple where FP is R11. Added minimal tests that load up ARM64 and the two flavors or ARM core files with a single thread and known register values in each register. Each register is checked for the exact value.

Differential Revision: https://reviews.llvm.org/D49750

llvm-svn: 338734