scripts: Ignore compatibility constants in wrapper

scripts: Ignore compatibility constants in wrapper

When the working group changes the name of a constant:

  VK_KHR_MAINTENANCE1_SPEC_VERSION ->
  VK_KHR_MAINTENANCE_1_SPEC_VERSION

they will still #define the original name to maintain backward
compatibility with existing code that uses it:

  #define VK_KHR_MAINTENANCE_1_SPEC_VERSION 2
  #define VK_KHR_MAINTENANCE_1_EXTENSION_NAME "VK_KHR_maintenance1"
  #define VK_KHR_MAINTENANCE1_SPEC_VERSION  VK_KHR_MAINTENANCE_1_SPEC_VERSION
  #define VK_KHR_MAINTENANCE1_EXTENSION_NAME VK_KHR_MAINTENANCE_1_EXTENSION_NAME

In this case, we need to ignore the non-numeric _SPEC_VERSION and
unquoted _EXTENSION_NAME constants because they don't define a separate
extension.