[PATCH] [PECOFF] Support linking against DLL.

[Rui Ueyama]

  Sean,

  It looks like obj2yaml outputs malformed YAML in the following cases:

   - Section name with special characters: COFF file often contains sections like @comp.id or .debug$S. These names should be quoted by "", otherwise yaml2obj cannot read them.
   - Empty section: If the size of a section is zero, obj2yaml outputs the following line, which cannot be parsed by obj2yaml

    SectionData:

  Looks like it needs to be

    SectionData: ""

http://llvm-reviews.chandlerc.com/D1096