Make lastIndexOf use the same cut-off between BMH as indexOf
Make lastIndexOf use the same cut-off between BMH as indexOf

Also update test to use a string longer than 52 characters
to test both BMH and linear path.

raulgrell/zig,zig-lang/zig,zig-lang/zig,andrewrk/zig,raulgrell/zig,raulgrell/zig,andrewrk/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig