PROJ/m4/ax_check_compile_flag.m4, branch 5.0

PROJ/m4/ax_check_compile_flag.m4, branch 5.0 Forked from https://github.com/OSGeo/PROJ Merge pull request #868 from cffk/geod-1.49.3 2018-03-19T14:07:21+00:00 Charles Karney charles@karney.com 2018-03-19T13:53:34+00:00 bb69e6e578a36a8501625f1239714d88b1685f67 Patch 1.49.3 for geodesic package. Closes #826, partially closes #843.

Patch 1.49.3 for geodesic package.

Closes #826, partially closes #843.