These comparisons work because our compiler uses string pooling.
What we want to do is check to see whether the pointer (e.g. clabel)
has changed. Because of string pooling, we are doing this. However,
a better fix would be to declare a string in each file and use it in
both the assignment and the comparison.

Note: we do not want to use strcmp, because we are concerned about the
pointer value, not the contents of the string. Even if the contents are
the same, we still want to free the memory if the pointer has changed.

./awt_Font.c(614): if (nativename && (nativename != ""))
./awt_FileDialog.c(803): if (cl && cl != "") {
./awt_MenuItem.c(357): if (clabel && (clabel != "")) {
./awt_Menu.c(259): if (ctitle != NULL && ctitle != "") {
./awt_Button.c(193): if (clabel != "") {
./awt_Button.c(258): if (clabel != "") {
./awt_TextField.c(487): if (cl != NULL && cl != "") {
./awt_TextField.c(532): if (cl != NULL && cl != "") {
./awt_Checkbox.c(188): if (clabel != "") {