tests: check HAVE_SNPRINTF before defining.
tests: check HAVE_SNPRINTF before defining.

bjori/libbson,remicollet/libbson,Machyne/libbson,mongodb/libbson,mongodb/libbson,Machyne/libbson,paulmelnikow/libbson,jqk6/libbson,mongodbinc-interns/libbson,alexeyvo/libbson,jqk6/libbson,ajdavis/libbson,paulmelnikow/libbson,paulmelnikow/libbson,rayyang2000/libbson,rayyang2000/libbson,4Second2None/libbson_tmp,rcsanchez97/libbson,4Second2None/libbson_tmp,mapr/libbson,ksuarz/libbson,derickr/libbson,remicollet/libbson,derickr/libbson,mongodbinc-interns/libbson,ajdavis/libbson,4Second2None/libbson_tmp,remicollet/libbson,4Second2None/libbson_tmp,rcsanchez97/libbson,bjori/libbson,Convey-Compliance/libbson,rayyang2000/libbson,Convey-Compliance/libbson,ksuarz/libbson,Convey-Compliance/libbson,remicollet/libbson,rayyang2000/libbson,bjori/libbson,ksuarz/libbson,paulmelnikow/libbson,mongodb/libbson,derickr/libbson,paulmelnikow/libbson,alexeyvo/libbson,mongodbinc-interns/libbson,rcsanchez97/libbson,Machyne/libbson,jqk6/libbson,alexeyvo/libbson,mapr/libbson,jqk6/libbson,ajdavis/libbson,derickr/libbson,mapr/libbson,mongodbinc-interns/libbson,Machyne/libbson