Unrolled build for rust-lang#121706

Rollup merge of rust-lang#121706 - Nadrieril:simplify-sort-candidate, r=matthewjasper

match lowering: Remove hacky branch in sort_candidate

Reusing `self.test()` there wasn't actually pulling a lot of weight. In particular the `TestKind::Len` cases were all already correctly handled.

r? `@matthewjasper`

Author: rust-timer

compiler/rustc_mir_build/src/build/matches/test.rs

@@ -583,10 +583,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 fully_matched = true;
                 Some(variant_index.as_usize())
             }
-            (&TestKind::Switch { .. }, _) => {
-                fully_matched = false;
-                None
-            }
 
             // If we are performing a switch over integers, then this informs integer
             // equality, but nothing else.
@@ -611,10 +607,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     options.len()
                 })
             }
-            (&TestKind::SwitchInt { .. }, _) => {
-                fully_matched = false;
-                None
-            }
 
             (
                 &TestKind::Len { len: test_len, op: BinOp::Eq },
@@ -703,34 +695,25 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     None
                 }
             }
-            (&TestKind::Range { .. }, _) => {
-                fully_matched = false;
-                None
-            }
 
-            (&TestKind::Eq { .. } | &TestKind::Len { .. }, _) => {
-                // The call to `self.test(&match_pair)` below is not actually used to generate any
-                // MIR. Instead, we just want to compare with `test` (the parameter of the method)
-                // to see if it is the same.
-                //
-                // However, at this point we can still encounter or-patterns that were extracted
-                // from previous calls to `sort_candidate`, so we need to manually address that
-                // case to avoid panicking in `self.test()`.
-                if let TestCase::Or { .. } = &match_pair.test_case {
-                    return None;
-                }
+            // FIXME(#29623): return `Some(1)` when the values are different.
+            (TestKind::Eq { value: test_val, .. }, TestCase::Constant { value: case_val })
+                if test_val == case_val =>
+            {
+                fully_matched = true;
+                Some(0)
+            }
 
-                // These are all binary tests.
-                //
-                // FIXME(#29623) we can be more clever here
-                let pattern_test = self.test(match_pair);
-                if pattern_test.kind == test.kind {
-                    fully_matched = true;
-                    Some(0)
-                } else {
-                    fully_matched = false;
-                    None
-                }
+            (
+                TestKind::Switch { .. }
+                | TestKind::SwitchInt { .. }
+                | TestKind::Len { .. }
+                | TestKind::Range { .. }
+                | TestKind::Eq { .. },
+                _,
+            ) => {
+                fully_matched = false;
+                None
             }
         };