Fixed a broken test suite test after recent editline merges.

The problem is that editline currently is trying to be smart when we paste things into a terminal window. It detects that input is pending and multi-line input is accepted as long as there is anything pending.

So if you open lldb and paste the text between the quotes:

"command regex carp
s/^$/help/

carp
"

We still still be stuck in the "command regex" multi-line input reader as it will have all three lines:

"s/^$/help/

carp
"

The true fix for this is something Kate Stone will soon work on:

- multi-line input readers must opt into this paste/pending input feature ("expr" will opt into it, all other commands won't)
- If we are in a multi-line input reader that requests this and stuff is pasted, then it will do what it does today
- if we start in a IOHandler that doesn't need/want pending input and text is pasted, and we transistion to a IOHandler that does want this functionality, then disable the pending input. Example text would be:

"frame variable
thread backtrace
expr
for (int i=0;i<10;++i)
  (int)printf("i = %i\n", i);

frame select 0
"

When we push the expression multi-line reader we would disable the pending input because we had pending input _before_ we entered "expr".

If we did this first:

(lldb) expr

Then we pasted:

"void foo()
{
}

void bar()
{
}
"

Then we would allow the pending input to not look for an empty line to terminate the expression. We filed radar 19008425 to track fixing this issue.