[parrot/parrot] 2c37c8: imcc: error on exceptions in constant folding

[GitHub]

  Branch: refs/heads/smoke-me/const-exc-gh1236
  Home:   https://github.com/parrot/parrot
  Commit: 2c37c8f4ff9cfe579acd15d12419394bf2a9fd1c
      https://github.com/parrot/parrot/commit/2c37c8f4ff9cfe579acd15d12419394bf2a9fd1c
  Author: Reini Urban <rurban at cpan.org>
  Date:   2017-06-05 (Mon, 05 Jun 2017)

  Changed paths:
    M compilers/imcc/optimizer.c
    M src/string/namealias.c
    M t/compilers/imcc/syn/const.t

  Log Message:
  -----------
  imcc: error on exceptions in constant folding

When an op with only constants args throws an exception like div by zero,
eval just returns the address of the handler, not the handler.  So we only
know that something is wrong, not what.

The exception message should be improved later.  For now just error with
eval_ins: unhandled exception for op '%s'

Fixes #1236