RT#77215 Increase MAXLINELENGTH to 80000

MM_Win32.pm sets by default MAXLINELENGTH (dmake related) to 64 * 1024
which is not enough e.g. for installing Date::Manip

The trouble is that the way MM_Win32.pm sets this value overrides all
dmake config files - for example in strawberry perl dmake is preconfigured
with MAXLINELENGTH := 800000 however MM_Win32.pm takes it down to 65536

Not sure what is the correct way to handle this. I would at least prefer
to increase the default value - my proposal is 800000

Rpeorted by kmx