optimize tetgen.cxx (but not predicates.cxx)

CMakeLists.txt

@@ -1181,7 +1181,7 @@ endif(NOWARN)
 check_cxx_compiler_flag("-O0" NOOPT)
 if(NOOPT)
   file(GLOB_RECURSE NOOPT_SRC Numeric/robustPredicates.cpp Mesh/BDS.cpp
-                              Parser/Gmsh.tab.cpp contrib/Tetgen*/*.cxx)
+                              Parser/Gmsh.tab.cpp contrib/Tetgen*/predicates.cxx)
   foreach(FILE ${NOOPT_SRC})
     get_source_file_property(PROP ${FILE} COMPILE_FLAGS)
     if(PROP)