bump minimum make version to 4.0 (for $(file …) function)

This already was a requirement for Windows for a few years now, and make
4.0 was released nearly 9 years ago, and it has been used in LO's build
system since it has been added 11 years ago while it was only available
in prerelease versions of make, providing an alternative workaround for
systems that didn't have make built from cvs… I guess it is finally time
to get rid of those workarounds and just require make 4.0 for everyone.

NOTE: reading files with the $(file …) function was only added with
version 4.2 of GNU make, and just using it without contents was added in
4.1, so those usages aren't supported

Change-Id: Ia1c2c86cfdbbd81f349bb9f7188299e16bdd155f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/143910
Tested-by: Jenkins
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>

0 files changed, 0 insertions, 0 deletions