performance-metrics: Add git committer date to the report

Signed-off-by: Bo Chen <chen.bo@intel.com>

performance-metrics/build.rs

@@ -27,10 +27,23 @@ fn main() {
         }
     }
 
+    let mut git_committer_date = "".to_string();
+    if let Ok(git_out) = Command::new("git")
+        .args(&["show", "-s", "--format=%cd"])
+        .output()
+    {
+        if git_out.status.success() {
+            if let Ok(git_out_str) = String::from_utf8(git_out.stdout) {
+                git_committer_date = git_out_str;
+            }
+        }
+    }
+
     // This println!() has a special behavior, as it will set the environment
     // variable GIT_human_readable, so that it can be reused from the binary.
     // Particularly, this is used from the main.rs to display the exact
     // version information.
     println!("cargo:rustc-env=GIT_HUMAN_READABLE={}", git_human_readable);
     println!("cargo:rustc-env=GIT_REVISION={}", git_revision);
+    println!("cargo:rustc-env=GIT_COMMITER_DATE={}", git_committer_date);
 }