target features that the caller function doesn't provide. This matches
the existing backend failure to inline functions that don't have
matching target features - and diagnoses earlier in the case of
always_inline.
Fix up a few test cases that were, in fact, invalid if you tried
to generate code from the backend with the specified target features
and add a couple of tests to illustrate what's going on.
This should fix PR25246.
llvm-svn: 252834