Don't pass local_pm to compile_test_general

This argument is only used to inhibit `#![allow(unused)]` for `//@ run-pass` UI
tests.

No callers actually need to override this value, even when doing unusual
things, so we can just look it up inside the method body instead.

src/tools/compiletest/src/runtest.rs

@@ -930,14 +930,13 @@ impl<'test> TestCx<'test> {
     }
 
     fn compile_test(&self, will_execute: WillExecute, emit: Emit) -> ProcRes {
-        self.compile_test_general(will_execute, emit, self.props.local_pass_mode(), Vec::new())
+        self.compile_test_general(will_execute, emit, Vec::new())
     }
 
     fn compile_test_general(
         &self,
         will_execute: WillExecute,
         emit: Emit,
-        local_pm: Option<PassMode>,
         passes: Vec<String>,
     ) -> ProcRes {
         let compiler_kind = self.compiler_kind_for_non_aux();
@@ -961,7 +960,7 @@ impl<'test> TestCx<'test> {
                     // Note that we use the local pass mode here as we don't want
                     // to set unused to allow if we've overridden the pass mode
                     // via command line flags.
-                    && local_pm != Some(PassMode::Run)
+                    && self.props.local_pass_mode() != Some(PassMode::Run)
                 {
                     AllowUnused::Yes
                 } else {

src/tools/compiletest/src/runtest/mir_opt.rs

@@ -18,7 +18,7 @@ impl TestCx<'_> {
 
         let passes = std::mem::take(&mut test_info.passes);
 
-        let proc_res = self.compile_test_general(WillExecute::No, Emit::Mir, None, passes);
+        let proc_res = self.compile_test_general(WillExecute::No, Emit::Mir, passes);
         if !proc_res.status.success() {
             self.fatal_proc_rec("compilation failed!", &proc_res);
         }

src/tools/compiletest/src/runtest/ui.rs

@@ -15,10 +15,12 @@ impl TestCx<'_> {
     pub(super) fn run_ui_test(&self) {
         if let Some(FailMode::Build) = self.props.fail_mode {
             // Make sure a build-fail test cannot fail due to failing analysis (e.g. typeck).
-            let pm = Some(PassMode::Check);
-            let proc_res =
-                self.compile_test_general(WillExecute::No, Emit::Metadata, pm, Vec::new());
-            self.check_if_test_should_compile(self.props.fail_mode, pm, &proc_res);
+            let proc_res = self.compile_test(WillExecute::No, Emit::Metadata);
+            self.check_if_test_should_compile(
+                self.props.fail_mode,
+                Some(PassMode::Check),
+                &proc_res,
+            );
         }
 
         let pm = self.pass_mode();