Auto merge of #142879 - Mark-Simulacrum:opt-cleanup, r=<try>

Remove dead instructions in terminate blocks

Opening as draft for perf. It looks like terminate blocks are actually pretty uncommon, and dead instructions shouldn't cost us much, so I'm not expecting any meaningful delta from this.

Author: rust-bors[bot]

compiler/rustc_codegen_gcc/src/builder.rs

@@ -1591,9 +1591,9 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
         (value1, value2)
     }
 
-    fn filter_landing_pad(&mut self, pers_fn: RValue<'gcc>) -> (RValue<'gcc>, RValue<'gcc>) {
+    fn filter_landing_pad(&mut self, pers_fn: RValue<'gcc>) {
         // TODO(antoyo): generate the correct landing pad
-        self.cleanup_landing_pad(pers_fn)
+        self.cleanup_landing_pad(pers_fn);
     }
 
     #[cfg(feature = "master")]

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1166,11 +1166,10 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         (self.extract_value(landing_pad, 0), self.extract_value(landing_pad, 1))
     }
 
-    fn filter_landing_pad(&mut self, pers_fn: &'ll Value) -> (&'ll Value, &'ll Value) {
+    fn filter_landing_pad(&mut self, pers_fn: &'ll Value) {
         let ty = self.type_struct(&[self.type_ptr(), self.type_i32()], false);
         let landing_pad = self.landing_pad(ty, pers_fn, 1);
         self.add_clause(landing_pad, self.const_array(self.type_ptr(), &[]));
-        (self.extract_value(landing_pad, 0), self.extract_value(landing_pad, 1))
     }
 
     fn resume(&mut self, exn0: &'ll Value, exn1: &'ll Value) {

compiler/rustc_codegen_ssa/src/traits/builder.rs

@@ -516,7 +516,7 @@ pub trait BuilderMethods<'a, 'tcx>:
 
     // These are used by everyone except msvc
     fn cleanup_landing_pad(&mut self, pers_fn: Self::Function) -> (Self::Value, Self::Value);
-    fn filter_landing_pad(&mut self, pers_fn: Self::Function) -> (Self::Value, Self::Value);
+    fn filter_landing_pad(&mut self, pers_fn: Self::Function);
     fn resume(&mut self, exn0: Self::Value, exn1: Self::Value);
 
     // These are used only by msvc