[patch] gccld not passing -export-dynamic to gcc for link

gccld passes -shared through if it's generating a shared library, but
if you're compiling a program that needs to have its symbols
externally accessible, it doesn't pass -export-dynamic through to gcc
for the final link.

The attached patch fixes this. I've tested with a small test case I
sent Chris, and with Python; both seem to work.

I also fixed some inaccurate comments in GenerateCode.cpp.

export-dynamic.diff (3.51 KB)

...but had tabs in it. Misha kindly reminded me off-list that this
was bad. Try this one instead.

export-dynamic.diff (3.67 KB)

Patch looks great, applied:

Thanks Nicholas!