refs #1433, #1550: fix compilation of uthash.h on Open WATCOM 1.3, LCC 2.4.1, Borland C/C++ (free command line tools) 5.5

git-svn-id: https://svn.modelica.org/projects/Modelica/trunk@7815 7ce873d0-865f-4ce7-a662-4bb36ea78beb