Don't eagerly remove all catches if try body is empty.

Stemmed from discussion here: http://forum.dlang.org/post/mailman.1094.1371164023.13711.digitalmars-d@puremagic.com

For now, allow the following code in the test suite to be compiled.  Required for gdc to scan for jumps into catch blocks that skip initialisation of exception pointers - also, code generated by dmd current SEGV's during runtime in test8b.

Both tests currently fail in gdc with error "cannot goto into catch block", but may fix that at a later date depending on whether or not the code should be considered valid.