message: Add isInt from LLVM MathExtras.h
diff: @@ -13,6 +13,13 @@ inline T signextend(const T x) {
  return s.x = x;
  }
  +/// Checks if an integer fits into the given bit width.
  +/// from LLVM MathExtras.h
  +template <unsigned N>
  +constexpr inline bool isInt(int64_t x) {
  + return N >= 64 || (-(INT64_C(1) << (N - 1)) <= x && x < (INT64_C(1) << (N - 1)));
  +}
  +
  constexpr uint32_t generateBitmask(int n) {
  // Generate bitmask. There might be a smarter way to do this
  uint32_t mask = 0;
  