Make make-target-delegates grok namespace scope op and template params

Make make-target-delegates grok namespace scope op and template params

The next patch will want to use gdb::array_view<int> as parameter type
of a target_ops method.  However, that runs into a
make-target-delegates limitation: target_debug_foo calls in
target-delegates.c for parameters/return types with namespace scope
operators ("::") or template parameters, end up looking like:

 @@ -1313,9 +1313,7 @@ debug_set_syscall_catchpoint (struct target_ops *self, int arg1, int arg2, int a
    fputs_unfiltered (", ", gdb_stdlog);
    target_debug_print_int (arg3);
    fputs_unfiltered (", ", gdb_stdlog);
 -  target_debug_print_int (arg4);
 -  fputs_unfiltered (", ", gdb_stdlog);
 -  target_debug_print_int_p (arg5);
 +  target_debug_print_gdb::array_view<const_int> (arg4);

which obviously isn't something that compiles.  The problem is that
make-target-delegates wasn't ever taught that '::', '<', and '>' can
appear in parameter/return types.  You could work around it by hidding
the unsupported characters behind a typedef in the target method
declaration, or by using an explicit TARGET_DEBUG_PRINTER, but it's
better to just remove the limitation.

While at it, also fix an "abuse" of reserved identifiers.

gdb/ChangeLog:

	* make-target-delegates (munge_type): Also munge '<', '>', and
	':'.  Avoid double underscores in identifiers, and trailing
	underscores.
	* target-debug.h
	(target_debug_print_VEC_static_tracepoint_marker_p__p): Rename to
	...
	(target_debug_print_VEC_static_tracepoint_marker_p_p): ... this.
	* target-delegates.c: Regenerate.