[svn r335] The basics of exception handling are in place. Still need to make sure calls are turned into invokes everywhere. (NewExpression for instance) Still some rough edges and corner cases to figure out. Needs testing!

module bug1;
struct Foo { Foo opSub(ref Foo b) { return Foo(); } }
struct Bar { Foo whee; }
void test(ref Bar moo) { Foo nngh; auto plonk = nngh - moo.whee; }
void main() { Bar bar; test(bar); }