Don't hard-code rustdoc subcommand

- Change `subcommand()` to take BuildKind and return Option
- Remove `is_build_kind_supported`

Author: jyn514

collector/src/bin/rustc-perf-collector/execute.rs

@@ -146,7 +146,7 @@ impl Profiler {
 
     // What cargo subcommand do we need to run for this profiler? If not
     // `rustc`, must be a subcommand that itself invokes `rustc`.
-    fn subcommand(&self) -> &'static str {
+    fn subcommand(&self, build_kind: BuildKind) -> Option<&'static str> {
         match self {
             Profiler::PerfStat
             | Profiler::PerfStatSelfProfile
@@ -158,27 +158,14 @@ impl Profiler {
             | Profiler::Callgrind
             | Profiler::DHAT
             | Profiler::Massif
-            | Profiler::Eprintln => "rustc",
-            Profiler::LlvmLines => "llvm-lines",
-        }
-    }
-
-    fn is_build_kind_allowed(&self, build_kind: BuildKind) -> bool {
-        match self {
-            Profiler::PerfStat
-            | Profiler::PerfStatSelfProfile
-            | Profiler::SelfProfile
-            | Profiler::TimePasses
-            | Profiler::PerfRecord
-            | Profiler::OProfile
-            | Profiler::Cachegrind
-            | Profiler::Callgrind
-            | Profiler::DHAT
-            | Profiler::Massif
-            | Profiler::Eprintln => true,
+            | Profiler::Eprintln => if build_kind == BuildKind::Doc {
+                    Some("rustdoc")
+                } else {
+                    Some("rustc")
+                },
             Profiler::LlvmLines => match build_kind {
-                BuildKind::Debug | BuildKind::Opt => true,
-                BuildKind::Check | BuildKind::Doc => false,
+                BuildKind::Debug | BuildKind::Opt => Some("rustc"),
+                BuildKind::Check | BuildKind::Doc => None,
             }
         }
     }
@@ -268,23 +255,19 @@ impl<'a> CargoProcess<'a> {
             // machinery works).
             let subcommand = if let Some((ref mut processor, run_kind, ..)) = self.processor_etc {
                 let profiler = processor.profiler();
-                if !profiler.is_build_kind_allowed(self.build_kind) {
-                    return Err(anyhow::anyhow!(
-                        "this profiler doesn't support {:?} builds",
-                        self.build_kind
-                    ));
-                }
                 if !profiler.is_run_kind_allowed(run_kind) {
                     return Err(anyhow::anyhow!(
                         "this profiler doesn't support {:?} runs",
                         run_kind
                     ));
                 }
 
-                if self.build_kind == BuildKind::Doc {
-                    "rustdoc"
-                } else {
-                    profiler.subcommand()
+                match profiler.subcommand(self.build_kind) {
+                    None => return Err(anyhow::anyhow!(
+                        "this profiler doesn't support {:?} builds",
+                        self.build_kind
+                    )),
+                    Some(sub) => sub,
                 }
             } else {
                 "rustc"