MCJIT emits zero-length CIE at the end of the _eh_frame section. This change
ensures that parser inside DebugInfo will not crash and correctly record such cases.
We are now recording DW_EH_PE_omit as a default value for FDE and LSDA encodings.
Also Offset != EndAugmentationOffset assertion check will only happen if augmentation
string had 'z' letter in it.
Differential Revision: http://reviews.llvm.org/D16588
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258931 91177308-0d34-0410-b5e6-96231b3b80d8