Switch from AX_CHECK_COMPILER_FLAGS to AX_CHECK_COMPILE_FLAG & AX_CHECK_LINK_FLAG from autoconf-archive to resolve build issues with legacy Darwin.
Syntax has been updated to autoconf 2.69 format, this paves the way for updating to 2.71, but that needs to be handled separately as the remaining files in m4 need updating to current autoconf-archive versions, as well as changes to configure.ac.
Switch from AX_CHECK_COMPILER_FLAGS to AX_CHECK_COMPILE_FLAG & AX_CHECK_LINK_FLAG from autoconf-archive to resolve build issues with legacy Darwin. Syntax has been updated to autoconf 2.69 format, this paves the way for updating to 2.71, but that needs to be handled separately as the remaining files in m4 need updating to current autoconf-archive versions, as well as changes to
configure.ac
.Resolves issue #193