gbuild-to-ide incompatibility with make 4.0

[Peter Foley]

While looking at the gbuild-to-ide script, I noticed that almost all
of the regex broke due to the below change in make 4.0.

* In -p output, .RECIPEPREFIX settings are shown and all target-specific
  variables are output as if in a makefile, instead of as comments.

I'm wondering if it would be fine to require make >= 4.0 to run this script?
Otherwise, two sets of regex would be needed, one for make 4.0+ and
one for older versions.
I'm going to try to get the script to work with make 4.0, but it would
be easier if I don't have to worry about old make versions.
Thoughts?

Thanks,

Peter