Measures time during eval/macro.
// Create when you want to start measuring.
final m = new MeasurePerformance();
//! DO SOMETHING THAT TAKES A WHILE
// Measure and print the time.
// %NANO% and %SECONDS% can also be used.
m.measure("That took %MILLI% milliseconds");
// Alternatively, get the time value directly as `UInt64`.
final time: eval.integers.UInt64 = m.timeSinceCreated();