for review: fix bug in scoping for higher order terms

[Lee Naish]

Fergus Henderson <fjh at cs.mu.OZ.AU> writes:

>compiler/make_hlds.m:
>	Implement the new rules for quantification of lambda expressions:
>	ensure that all variables in arguments of predicate or function
>	lambda expressions are locally quantified, but that variables
>	in the return value term of function lambda expressions are
>	not locally quantified.

s/not locally quantified/quantified according to the normal rules/

Otherwise fine according to my (brief) look.

	lee