Print the location of the ShouldNotReachHere, to help Pat track down a
bug

[Tracking bug 21562]

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 118103]
Report compile failures correctly

Formerly was silently failing to build the shared library

[Tracking bug 21562]

[git-p4: depot-paths = "//depot/software/common/ConsensusCore/": change = 118104]