Fix exception handling line table problems introduced by r173593

r173593 made us a little too eager to associate all code at the end of a
function with the user-written 'return' line. This caused problems with
breakpoints as they'd be set in exception handling code preceeding the
actual non-exception return handling code, leading to the breakpoint never
being hit in non-exceptional execution.

This change restores the pre-r173593 exception handling line information where
the cleanup code is associated with the '}' not the return line.