Fix "on target" variables during header scan, from Matt Armstrong.
Setting target-specific variables while under the influence of
the target's target-specific variables caused the _global_ values
to be modified. This happened both during header file scanning
and with the "on target statement" syntax.
The manifestation of this was if a file #included itself, HdrRule
would accidentally set HDRRULE/HDRSCAN globally, and then all
files (executables, etc) would get scanned for includes.
While this borrows from Matt's fix, it is a slightly different
User visible fix documented in RELNOTES.
=== computer:1666: Change 39095 by seiwald@play-seiwald on 2002/12/17 14:00:58