8198717: Remove compute_optional_offset
Summary: remove optional_offset computation and related unused code from javaClasses for reflection.
Reviewed-by: redestad, lfoltan
martin [Wed, 19 Sep 2018 10:51:06 -0700] rev 51805
8209817: stack is executable when building with Clang on Linux
Reviewed-by: dholmes, martin, mikael, ihse
Contributed-by: Arthur Eubanks <aeubanks@google.com>