repeat.t: Remove to-do test for 20010809.028

Aka #7505, the bug was that list repeat didn’t copy its
elements.  But list repeat hasn’t copied its elements for
years now, and code could be relying on the current
behaviour of foreach(($var)x2) { ... } which aliases $_
to $var twice.  We also have tests for the current
behaviour.
pp.c:pp_repeat: Remove #if 0 code

This was intended to fix 20010809.028, but treating
20010809.028 as not-a-bug is the only way to preserve
backward-compatibility.  See the previous commit’s
explanation.
[perl #122695] Fix line number for else{foo}

where there is no space after the opening brace.

The code that was responsible for the wrong line number:

	if (isSPACE(*s) || *s == '#')
	    PL_copline = NOLINE;   /* invalidate current command line number */

was added in perl *2.0* (378cc40b3)!  It looked a little different
back then:

	if (isspace(*s) || *s == '#')
	    cmdline = NOLINE;   /* invalidate current command line number */

I don’t know what the condition was for.  I can only imagine that it
seemed logical to skip the setting of cmdline if it appeared to be
something on the same line (e.g., if($foo){bar()} as opposed to
if($foo){<newline>...}).  Clearly that doesn’t work for ‘else{foo()}’
because we end up giving that statement the line number where the
‘if’ occurs.  (cmdline/PL_copline is for remembering the first line of
a multi-line construct.)