Herbert Valerio Riedel authored Nov 19, 2015 and Ben Gamari committed Nov 19, 2015

First of all, we need to use -mminimal-toc on IBM AIX

AIX's XCOFF is limited to 16k entries in its TOC for 32bit compilation,
which quickly overflows with GHC's code generation.

Otoh, the Parser.hs module contains more entries than fit into a
minimal-toc, so we need to switch back to `-mfull-toc` for that single
module again.

Then, we also need to set the `THREAD_SAFE` CPP #define in order to
unlock the thread-safe `errno` which is essential for the threaded
runtime.

Depends on D1501

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie, erikd

Differential Revision: https://phabricator.haskell.org/D1502