message: miri build script: use incremental builds
diff: @@ -49,6 +49,7 @@ fi
  # We enable debug-assertions to get tracing.
  # We enable line-only debuginfo for backtraces.
  export RUSTFLAGS="-C link-args=-Wl,-rpath,$LIBDIR -C debug-assertions -C debuginfo=1 $RUSTC_EXTRA_FLAGS"
  +export CARGO_INCREMENTAL=1
  ## Helper functions
  