While fixing JDK-8301753, I tried running the make tests on GNU make 4.4. It turns out one vardep test fails:

Running test 'special:make:make-base'
TestMakeBase.gmk:323: *** Wrong contents in vardep file. Stop.
FAILURE: Wrong contents in vardep file
Expected: >foo '""' "''" bar \$ORIGIN &#x00a9<
Actual: >foo '""' "''" bar \$ORIGIN &<
gmake[4]: *** [TestMake.gmk:31: make-base] Error 2
Finished running test 'special:make:make-base'

Apparently some parsing has changed somewhere between make 4.0 and make 4.4, which makes anything following the `#` to be ignored; presumably by being interpreted as a comment. This is despite our best efforts to avoid this (and which works in make 3.81 and 4.0)