Kouhei Yanagita

I removed `Numeric#ceildiv`. The PR contains only `Integer#ceildiv`.

I tried benchmarking. As shown below, nobu-san's suggestion is faster. Thank you! ```ruby require 'benchmark' n = 10 ** 7 Benchmark.bm do |x| x.report("Fixnum/Fixnum") { a, b = 5, 2;...

In this case, `OPTIMIZED_CMP` appears to be beneficial. ```diff diff --git a/array.c b/array.c index 1032696308..3e34e17111 100644 --- a/array.c +++ b/array.c @@ -5251,9 +5251,12 @@ recursive_cmp(VALUE ary1, VALUE ary2, int recur)...

Yes, I was aware that the configuration strings differ between bash and zsh. I believe the options are either to prepare a single environment variable and ask users to configure...