[llvm-readobj] Add a flag to dump just the section-to-segment mapping.
The following patch introduces a new function printSectionMapping which is responsible for dumping just the section-to-segment mapping.
This patch also introduces a n option -section-mapping that outputs that mapping without the program headers.
Previously, this functionality was controlled by printProgramHeaders, and the output from -program-headers has not been changed. I am happy to change the option name, I copied the name that was displayed when outputting the mapping table.
Reviewers: khemant, jhenderson, grimar, rupprecht
Reviewed By: jhenderson, grimar, rupprecht
Subscribers: rupprecht, jhenderson, llvm-commits
Differential Revision: https://reviews.llvm.org/D57365