The problem is xpdf depends on lesstif, it will bring libXt.la. But lesstif cannot be built now for some reasons.
D Morgan asked us to say if removal of .la files broke anything. It breaks xpdf, and I don't know if it's fixable. xpdf needs libXt.la to build libxpdf.la, and the xpdf build is heavily dependent on libxpdf.la. See xpdf-3.03-shared.diff for example.