The Ubuntu equivalent would be libc6-dev, but I can\'t seem to find it for Solaris?
libc6-dev
How can I get types.h and related files for building packages on Solaris
Assuming you use IPS 'pkg search 'types.h''
The Oracle Solaris 11 Cheat Sheet for Image Packaging System could be useful, too.
You need the system/header package.
I found this via http://pkg.oracle.com/solaris/release/en/search.shtml?token=types.h&action=Search