This introduces the YAML output style and implements dumping of the MSF headers to YAML. This is the smallest possible patch to get basic support for YAML output working. After I confirm I'm using the library correctly and that the code I've written is sufficiently "yamlish" (like pythonic), I'll iterate more quickly with post commit reviews.
Output looks like this currently:
D:\src\llvmbuild\ninja>bin\llvm-pdbdump.exe -raw-headers -raw-output-style=YAML d:\FileCheck.pdb --- MSF: BlockSize: 4096 Unknown0: 1 NumBlocks: 1767 NumDirectoryBytes: 6728 Unknown1: 0 BlockMapAddr: 1558 NumDirectoryBlocks: 2 BlockMapOffset: 6381568 DirectoryBlocks: - 1556 - 1557 NumStreams: 131 ...