review (S) for 6926979: should simplify catch_inline_exception

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/6926979

6926979: should simplify catch_inline_exception
Reviewed-by:

This is the follow on fix to 6877221 that I'm proposing for hs18.
That fix patched over some uncommon trap conditions that could result
in unneeded uncommon traps during exception dispatch.  This fix
rewrites the exception paths to take advantage of the fast subtype
checks to handle more cases inline and removes the use of the uncommon
trap that used Reason_unhandled/Action_none to deal with unloaded
classes or classes with subtypes.  Instead we emit full subtype checks
for catch classes with subclass and allow catch_call_exceptions to
emit a Reason_unloaded exception handler for unloaded catch classes.
This way we won't uncommon trap unless we really need to and in that
case we'll throw out the code and recompile.

src/share/vm/opto/doCall.cpp
src/share/vm/opto/parse.hpp
src/share/vm/opto/parse1.cpp