Print dylib load kind (weak, reexport, etc) in llvm-objdump -m -dylibs-used

Summary:
Historically llvm-objdump prints the path to a dylib as well as the
dylib's compatibility version and current version number. This change
extends this information by adding the kind of dylib load: weak,
reexport, etc.

rdar://51383512

Reviewers: pete, lhames

Reviewed By: pete

Subscribers: rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62866

llvm-svn: 363746