Does the mid-2010 Macbook Pro (Core 2 Duo) support memory compression with OS X 10.9+?
It is implemented completely in software, yes (for any meaningful definition of this). Obviously you will need a physical CPU to run the code in practice.

The feature does not require the AESNI instruction set. It only requires a x86_64 CPU (i.e. 64-bit CPU) which is anyways already a requirement for running Mavericks.

You can find the source code for the compression algorithm here:

https://github.com/aosm/xnu/blob/9653931b282e653805655cc56831195d0fb162aa/osfmk/x86_64/WKdmCompress_new.s