Re: Make the ninja backend transitively check for C++ sources to use the C++ compiler for linking (issue 2219123002 by ted.mielczarek@gmail.com)

[tha...@chromium.org]

(fwiw, this was intentional to match Xcode's behavior -- back then, my goal was
that switching between xcode and ninja on Mac should produce identical behavior
so that having a ninja generator in addition to Xcode isn't a big maintenance
burden. I don't mind this changing, but you didn't update the test that checked
for this behavior, which caused some confused thrashing:
https://bugs.chromium.org/p/gyp/issues/detail?id=526)

https://codereview.chromium.org/2219123002/