Use Ruby 1.9.3 now as base for cross-compilation

In the past, the only version that was capable of cross-compile
and target 1.8.7 was *just* 1.8.7.

But now, 1.8.7 is no longer capable of cross-compile to 2.1.x,
which put us in a weird situation for those gems that still need
or want to support 1.8.7

After some testing, seems that Ruby developers have patched the
issues around `mkmf` and backported into Ruby 1.9.3, which is now
capable of cross-compile to Ruby 1.8.7, yay!

Once again, regressions that are not regressions and happy endings
for those who still are forced to maintain compatibility with
Ruby 1.8.7.

Author: luislavena

bin/package_win32_fat_binary

@@ -12,10 +12,10 @@ cd '/vagrant'
 # passed in path of gem to be cross-compiled
 cd $1
 
-base_version=${BASE_VERSION:-1.8.7-p374}
+base_version=${BASE_VERSION:-1.9.3}
 cc_versions=${RUBY_CC_VERSION:-1.8.7:1.9.3:2.0.0:2.1.4}
 
-# need to use 1.8.7 for fat-binaries (1.9.3 can't cross-build 1.8.7)
+# Use Ruby 1.9.3 as base to cross-compile to different versions
 rvm use $base_version
 bundle install