[llvm-pdbdump] Provide a mechanism to dump the raw contents of a PDB

A PDB can be thought of as a very simple file system.  It is
occasionally illuminating to see the contents of the underlying files.

Differential Revision: http://reviews.llvm.org/D13674

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250356 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed