[patch] Fix minmodules empty vmt

It seems that certain compilers feel that throwing an error for an assumed-size C array with an empty initializer is justified  (e.g.,

int x[] = {};

but that unsupported inlined assembly sequences are only worthy of a warning.  Whatevs.  It turns out that the --minimal-modules flag runs afoul of this by creating an empty virtual method table.  The fix is simply to drop a single NULL pointer into the initializer list in this case (we had a similar fix somewhat higher in this file for another array that is much more likely to be empty in traditional compilations, so I essentially took that same approach here, simply with a different trigger condition).