rust/chg/build.rs

dirstatemap: use the default code to handle "merged" case

This simplify the conditionnal a bit since most of it is handled by the common
code.

Differential Revision: https://phab.mercurial-scm.org/D11329

fn main() {
    cc::Build::new()
        .warnings(true)
        .file("src/sendfds.c")
        .file("src/sighandlers.c")
        .compile("procutil");
}