Auto merge of #42900 - sfackler:jemalloc-tweak, r=alexcrichton

Stop disabling fill in jemalloc

The underlying bug has been fixed for over 2 years!

r? @alexcrichton

src/liballoc_jemalloc/build.rs

@@ -137,8 +137,6 @@ fn main() {
         cmd.arg("--enable-debug");
     }
 
-    // Turn off broken quarantine (see jemalloc/jemalloc#161)
-    cmd.arg("--disable-fill");
     cmd.arg(format!("--host={}", build_helper::gnu_target(&target)));
     cmd.arg(format!("--build={}", build_helper::gnu_target(&host)));