Renamed copy_type() to copy_pike_type() to avoid conflict with <mach/mach.p>.

Rev: src/builtin_functions.c:1.357
Rev: src/language.yacc:1.242
Rev: src/las.c:1.249
Rev: src/operators.c:1.134
Rev: src/pike_types.c:1.177
Rev: src/pike_types.h:1.71
Rev: src/program.c:1.308