Add diesel to the benchmark suite

This commit adds diesel to the continuosly run benchmark suite. Diesel
heavily relies internally on macro generated code. Additionally there
are lots of complicated trait releations used as part of their API.
Therefore this benchmark will be quite sensitive to:
* Performance related changes in the macro expanding code
* Performance related changes while resolving trait bounds

CC #7950

Author: weiznich

xtask/src/metrics.rs

@@ -26,7 +26,7 @@ impl flags::Metrics {
         }
         {
             let _d = pushd("./target/rustc-perf")?;
-            cmd!("git reset --hard 1d9288b0da7febf2599917da1b57dc241a1af033").run()?;
+            cmd!("git reset --hard c52ee623e231e7690a93be88d943016968c1036b").run()?;
         }
 
         let _env = pushenv("RA_METRICS", "1");
@@ -35,6 +35,7 @@ impl flags::Metrics {
         metrics.measure_analysis_stats_self()?;
         metrics.measure_analysis_stats("ripgrep")?;
         metrics.measure_analysis_stats("webrender")?;
+        metrics.measure_analysis_stats("diesel/diesel")?;
 
         if !self.dry_run {
             let _d = pushd("target")?;