autocorres: add "no_opt" option to turn off some simplifications.

No guarantee that this will make autocorres produce the output you want, or produce output at all.

JIRA issue: VER-428
Fix for struct-literal-initialisation with pointer-type fields.

JIRA VER-310
autocorres: Add test case for struct initializers.

Previously the C parser emitting incorrect code, causing AutoCorres to
fail. This test should pass now that the C parser's code generator has
been tweaked.