Object: iterator_range accessors for ObjectImage symbols and sections.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206767 91177308-0d34-0410-b5e6-96231b3b80d8
Tidy up. Remove extraneous typedef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206768 91177308-0d34-0410-b5e6-96231b3b80d8
[rtdyld,c++11] Range'ify symbol table walking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206769 91177308-0d34-0410-b5e6-96231b3b80d8