Estimated hours taken: 2
compiler/polymorphism.m:
Abort if there is a polymorphic unification that is in
a partially instantiated mode. This error should be
caught earlier (probably during mode analysis), but it's
best to abort rather than just go ahead and generate
bad code.
tests/invalid/polymorphic_unification.m:
tests/invalid/polymorphic_unification.err_exp:
A test case for the above change.
tests/invalid/Mmakefile:
Turn this test case on.
