Jordan Rose 3243f21280 Make sure all failures to load module interfaces are diagnosed (#25636) ...

...specifically, diagnosed in the parent DiagnosticEngine. This not
only provides a better user experience, but makes sure that the
compiler exits with a nonzero exit code even if the module goes
unused.

rdar://problem/50789839

2019-06-20 14:14:38 -07:00

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failing-overlay

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