libcxxabi patch: respect NDEBUG

zig patch: respect NDEBUG. Otherwise the file path makes it into the
binary, causing non-reproducible builds.

Author: andrewrk

lib/libcxxabi/src/abort_message.h

@@ -15,6 +15,11 @@ extern "C" _LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN void
 abort_message(const char *format, ...) __attribute__((format(printf, 1, 2)));
 
 #ifndef _LIBCXXABI_ASSERT
+// zig patch: respect NDEBUG. Otherwise the file path makes it into the binary,
+// causing non-reproducible builds.
+#ifdef NDEBUG
+#define _LIBCXXABI_ASSERT(a,b) (void)0
+#else
 #  define _LIBCXXABI_ASSERT(expr, msg)                                                                                 \
     do {                                                                                                               \
       if (!(expr)) {                                                                                                   \
@@ -24,5 +29,6 @@ abort_message(const char *format, ...) __attribute__((format(printf, 1, 2)));
     } while (false)
 
 #endif
+#endif
 
 #endif // __ABORT_MESSAGE_H_