pretty -native -injected-sources -injected-source-content works with this patch, and produces identical output to the dia version
- I'd like to get feedback on the high-level design here, since I'm not familiar with how things are supposed to be done in this code. In particular, does the split between NativeEnumInjectedSources and InjectedSourceStream make sense? Are these names consistent with the rest of the code?
- The injected source _writing_ is done in PDBFileBuilder. Now that InjectedSourceStream exists, should there be a InjectedSourceStreamBuilder that does the building part? (If so, probably in a follow-up)
(I wish I had had this when working on PR41626, and when I was looking at natvis stuff again the other day I realized I had almost forgotten all this stuff again. So I figured I'd try to implement this while I still remember it.)