message: Fix check that at least one target is enabled
diff: @@ -242,6 +242,10 @@ find_package(FLEX 2.6 REQUIRED)
  set (ISPC_MASKS 1 8 16 32 64)
  +if (NOT X86_ENABLED AND NOT ARM_ENABLED AND NOT WASM_ENABLED AND NOT GENX_ENABLED)
  + message( FATAL_ERROR "Either X86, ARM, WASM or GENX targets need to be enabled.")
  +endif ()
  +
  if (X86_ENABLED)
  list(APPEND ISPC_TARGETS
  sse2-i32x4 sse2-i32x8
  