[llvm-readobj] - Rewrite reloc-types.test to use YAML. NFCI.

This change rewrites and splits reloc-types.test
to use yaml2obj instead of precompiled binaries.
That allowed to remove 7 precompiled objects from the inputs.

I took the existent objects, used obj2yaml on them, simplified the result and
used yaml2obj in the test case with the result.

Notes:
* I converted, but did not remove relocs.obj.elf-i386, relocs.obj.elf-x86_64 or relocs.obj.elf-mips objects
because found they are used in other tests. 
* I was unable to convert relocs.obj.elf-ppc64, because obj2yaml hangs on this file for me.
* I was unable to convert relocs.obj.macho-arm, relocs.obj.macho-i386 and relocs.obj.macho-x86_64
because the output produced by obj2yaml does not seem to be correct.
* Because of the above I did not remove the script for creating all
of those objects: test\tools\llvm-readobj\Inputs\relocs.py

Differential revision: https://reviews.llvm.org/D62594

llvm-svn: 362089