Add optional execution of extended benchmarks

This change introduces a safe way to load and run extended benchmarks by using `pcall` with `require`. It ensures the main benchmarks remain unaffected if the extended module is unavailable or causes an error. This is perfect for omitting more complicated benchmarks from the 160k diskette version and also demonstrates how pcall can be used to load Lua modules even on operating systems that don't traditionally have linking libraries.

Author: Lethja

demo/minimum/bench.lua

@@ -164,6 +164,7 @@ benchmark_div()
 benchmark_pi()
 benchmark_gcd()
 benchmark_array()
+pcall(require, "exbench") -- Optionally run extended benchmarks
 
 -- Print memory and total time summary at the end of the table
 PrintLine()