Made the conversion to Elf_Relr explicit.

Some updates from the testing front:

Added some comments, plus some minor edits.

Thanks for the patch. Things look much cleaner now.

Applied patch from pcc and made --use-android-relr-tags independent of --pack-dyn-relocs.

Reverted the enum class for --pack-dyn-relocs.
Added class RelativeReloc that is similar to DynamicReloc but only stores relative relocations.
Added class RelrBaseSection that is similar to RelocationBaseSection but stores RelativeRelocs instead of DynamicRelocs.
RelrPackedRelocationSection now inherits from RelrBaseSection.
Updated test to add a relative relocation with odd offset.

Added an enum class for the --pack-dyn-relocs flag.
Added another option "android+relr" that implies both "android" and "android-relr" packing.
Another place in Relocations.cpp needed change to add relative relocations in RelrDyn instead of RelaDyn.
Relocations are only added to RelrDyn if "Sec.Alignment >= 2 && Offset % 2 == 0".

LGTM, sorry for the back and forth!

Decoding relr relocations is the default now for both -relocations and -dyn-relocations.
A new flag -raw-relr affects -relocations, turns off decoding and display raw SHT_RELR contents instead.

Relr is now defined directly as packed<uint>.
Added comment describing the SHT_RELR encoding.
Moved the logic for adding a relr relocation to Relocations.cpp.
RelocationBaseSection::addReloc is no longer a virtual function.

Relr is now defined directly as packed<uint>.
struct Elf_Relr_Impl is no longer necessary.

Write addend in section data only for the relocations in .relr.dyn.

Added tests, ready for review.

This patch depends on https://reviews.llvm.org/D47919

Apologies for the delay in updating this patch.

Added tests, ready for review.

I'm still working on adding some unit tests, but I thought I'd send this in for now in case there is any high level feedback on the overall approach.

Thanks for the review.
Can you land this one as well. I am new to llvm and don't have commit access.

Can you land it as well. I am new to llvm and don't have commit access.
Thanks.

Renamed android_relas -> AndroidRelas

Thanks for the review.
If everything looks good, can you land it as well.
This is my first change. I don't have write permissions to the repo.

Use CHECK-NEXT to match p2align.

Minimized test case.

Updated the comment and CHECK directives to match each other.

Moved EmitAlignment() out of the loop.

80-char line length limit, and use '-relocation-model=pic' instead of '--relocation-model=pic'.

In D44848#1047258, @mgrang wrote:

You can add the test in llvm as an ll file.

Added a unit test.

In D44848#1047203, @mgrang wrote:

Can you please add a unit test?