[JIT] Fix some more missing endian conversions in RuntimeDyld

Summary: This fixes MachO_i386_eh_frame.s on a big-endian Mips host.

Reviewers: lhames

Reviewed By: lhames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221047 91177308-0d34-0410-b5e6-96231b3b80d8