[gc] avoid asan heap-buffer-overflow with str_copy

use the proper API to set the pmc flag.
repro with
  ./parrot_old -D101 -t11 --gc inf --gc-debug --gc-nursery-size=0.0001 t/stress/gc_16.pir
Makefile: remove duplicate src/longopt.o

Fixes GH #1121
Also remove GEN_CONFIGS, GEN_MAKEFILES from archclean.
trace: add -t10 PARROT_TRACE_OPS_PMC_FLAG

To print the PMC flags with -t1 use now -t11.