There's a typo in the code - it should be "SvREFCNT" not "svREFCNT" in the get_refcnt() function. But I don't think that would produce the errors you see.
I have no idea what is producing those errors. I have never seen "Asembler messages" produced when running Inline::C code. Are you generally able to build perl extensions (ie modules whose source includes XS files) ? Can you show us what the XS file that Inline::C generated in the build directory looks like.
Once the typo is fixed, the code compiles and runs correctly for me on both Win32 and Linux (mandrake-9.1).