add a pragma...

Author: kkaefer

include/protozero/varint.hpp

@@ -37,8 +37,11 @@ namespace detail {
         uint64_t val = 0;
 
         if (iend - p >= max_varint_length) {  // fast path
-            __builtin_assume(iend - p >= max_varint_length);
             do {
+// GCC 12 has trouble understanding that we're not actually taking this branch for short buffers.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
                 int64_t b = *p++;
                           val  = ((static_cast<uint64_t>(b) & 0x7fU)       ); if (b >= 0) { break; }
                 b = *p++; val |= ((static_cast<uint64_t>(b) & 0x7fU) <<  7U); if (b >= 0) { break; }
@@ -50,6 +53,7 @@ namespace detail {
                 b = *p++; val |= ((static_cast<uint64_t>(b) & 0x7fU) << 49U); if (b >= 0) { break; }
                 b = *p++; val |= ((static_cast<uint64_t>(b) & 0x7fU) << 56U); if (b >= 0) { break; }
                 b = *p++; val |= ((static_cast<uint64_t>(b) & 0x01U) << 63U); if (b >= 0) { break; }
+#pragma GCC diagnostic pop
                 throw varint_too_long_exception{};
             } while (false);
         } else {