Disable tests requiring sunrpc when the relevant headers are missing.
In order to accommodate that, move the header check
from sanitizer_common to base-config-ix, and define the check result
as a global variable there. Use it afterwards both for definition
needed by sanitizer_common, and to control 'sunrpc' test feature.
While at it, remove the append_have_file_definition macro that was used
only once, and no longer fits the split check-definition.
Bug report: https://github.com/google/sanitizers/issues/974
Differential Revision: https://reviews.llvm.org/D47819
llvm-svn: 351109
965517fdad