Change 97369c4 is probably incorrect

[siddhesh]

I was looking at patches to pull into stock luajit and found the following:

commit 97369c48070d88238dcd45488b296fec693a2dfe (tag: v2.1-20160517) Author: Yichun Zhang (agentzh) Date: Tue May 17 14:25:11 2016 -0700

removed the GCC 4 requirement for x86 for older systems like Solaris i386.

The change claims to remove the gcc 4.0 minimum requirement check for x86 but the check is in #if LJ_TARGET_X64, which it doesn't look right since it should not be processed for i386.

I could not find a related PR or issue for this, so can you please help me understand this change better? Thanks!