Rollup merge of rust-lang#56702 - wesleywiser:calc_total_time_stats, r=michaelwoerister

[self-profiler] Add column for percent of total time

Example output:

```
Self profiling results:

| Phase            | Time (ms)      | Time (%) | Queries        | Hits (%)
| ---------------- | -------------- | -------- | -------------- | --------
| Parsing          | 3              | 0.52     |                |
| Expansion        | 64             | 11.27    |                |
| TypeChecking     | 13             | 2.36     | 35208          | 90.77
| BorrowChecking   | 0              | 0.10     | 68             | 50.00
| Codegen          | 22             | 3.82     | 7362           | 75.12
| Linking          | 252            | 43.81    | 458            | 68.56
| Other            | 219            | 38.12    | 47372          | 56.84

Optimization level: No
Incremental: off

```

cc @michaelwoerister

Author: pietroalbini

src/librustc/util/profiling.rs

@@ -62,11 +62,15 @@ macro_rules! define_categories {
             }
 
             fn print(&self, lock: &mut StderrLock<'_>) {
-                writeln!(lock, "| Phase            | Time (ms)      | Queries        | Hits (%) |")
+                writeln!(lock, "| Phase            | Time (ms)      \
+                                | Time (%) | Queries        | Hits (%)")
                     .unwrap();
-                writeln!(lock, "| ---------------- | -------------- | -------------- | -------- |")
+                writeln!(lock, "| ---------------- | -------------- \
+                                | -------- | -------------- | --------")
                     .unwrap();
 
+                let total_time = ($(self.times.$name + )* 0) as f32;
+
                 $(
                     let (hits, total) = self.query_counts.$name;
                     let (hits, total) = if total > 0 {
@@ -78,11 +82,12 @@ macro_rules! define_categories {
 
                     writeln!(
                         lock,
-                        "| {0: <16} | {1: <14} | {2: <14} | {3: <8} |",
+                        "| {0: <16} | {1: <14} | {2: <8.2} | {3: <14} | {4: <8}",
                         stringify!($name),
                         self.times.$name / 1_000_000,
+                        ((self.times.$name as f32) / total_time) * 100.0,
                         total,
-                        hits
+                        hits,
                     ).unwrap();
                 )*
             }