* test_functions: properly add dependencies of the array on test
   functions and test names so that the order comes out correctly.
 * fix lowering of struct literals to add parentheses around the type
   name.
 * omit const qualifier in slices because otherwise slices cannot be
   reassigned even when they are local variables.
 * special case pointer to functions and double pointer to functions in
   renderTypeAndName. This code will need to be cleaned up but for now
   it helps us make progress on other C backend stuff.
 * fix slice element access to lower to `.ptr[` instead of `[`.
 * airSliceElemVal: respect volatile slices