Make sure that symbols needed to implement runtime support for gcov are
exported when using an export list on Darwin.
Without the clang driver exporting these symbols, the linker hides them,
resulting in tapi verification failures.
rdar://45944768
Differential Revision: https://reviews.llvm.org/D55151
llvm-svn: 348187
Some weak external symbols were added to the profile runtime in D49953,
and on Darwin, these need to be exported for tapi verification purposes.
I've tightened the test so that future breakages can be caught earlier.
rdar://45831054
llvm-svn: 346276
Vedant Kumar