vector that represents the .o file at once, build up a vector for each
section of the .o file. This is needed because the .o file writer needs
to be able to switch between sections as it emits them (e.g. switch
between the .text section and the .rel section when emitting code).
This patch has no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22453 91177308-0d34-0410-b5e6-96231b3b80d8
5f48ff7d1f