Removes exception handler inlinining from -optimize

Exception handler inlining is an optimization that’s hard to get right
(and in fact has open bugs) but that has questionable benefits. This
commit removes -inlineHandlers from being included under -optimize. If
there are no serious repercussions then the optimization may be entirely
removed later.
remove InlineExceptionHandlers from the compiler

The main use case for this optimization is
leaner control flow upon inlining breakable/break,
as discussed in https://github.com/scala/scala/pull/3159.