Oh, bother. In Tru64 cc -std1 was looking rather nice

Oh, bother. In Tru64 cc -std1 was looking rather nice
in speed (upto 20% speedup in certain operations) but meanwhile
regexps and arithmetics got slower (5-10%) (according to
perlbench average speedup is negligible, and within measuring
flutter, 1%).  Therefore retracting all the changes
aimed at getting -std1 to compile cleanly:  #12475, #12476,
#12479, #12480, #12481, #12482, #12483, #12484.

p4raw-id: //depot/perl@12485