Bugfix/fix avx512vbmi regressions (#335)

Multiple AVX512VBMI-related fixes:

src/nfa/mcsheng_compile.cpp: No need for an assert here, impl_id can be set to 0
src/nfa/nfa_api_queue.h: Make sure this compiles on both C++ and C
src/nfagraph/ng_fuzzy.cpp: Fix compilation error when DEBUG_OUTPUT=on
src/runtime.c: Fix crash when data == NULL
unit/internal/sheng.cpp: Unit test has to enable AVX512VBMI manually as autodetection does not get trigger, this causes test to fail
src/fdr/teddy_fat.cpp: AVX512 loads need to be 64-bit aligned, caused a crash on clang-18

src/nfa/nfa_api_queue.h

@@ -251,7 +251,11 @@ void q_skip_forward_to(struct mq *q, s64a min_loc) {
 // Dump the contents of the given queue.
 static never_inline UNUSED
 void debugQueue(const struct mq *q) {
+#ifdef __cplusplus
     if (q == nullptr) {
+#else
+    if (q == NULL) {
+#endif
        DEBUG_PRINTF("q=NULL!\n");
        return;
     }