Add assertions for matches that used to use analyze_branch (#5733)

Following up from #5730, add debug assertions to ensure that new branch instructions don't slip through matches that used to use analyze_branch.

cranelift/codegen/src/dominator_tree.rs

@@ -372,7 +372,7 @@ impl DominatorTree {
                     }
                     self.push_if_unseen(*dest);
                 }
-                _ => {}
+                inst => debug_assert!(!inst.opcode().is_branch()),
             }
         }
     }

cranelift/codegen/src/flowgraph.rs

@@ -141,7 +141,7 @@ impl ControlFlowGraph {
                         self.add_edge(block, inst, *dest);
                     }
                 }
-                _ => {}
+                inst => debug_assert!(!inst.opcode().is_branch()),
             }
         }
     }

cranelift/codegen/src/inst_predicates.rs

@@ -204,7 +204,7 @@ pub(crate) fn visit_block_succs<F: FnMut(Inst, Block, bool)>(
                 }
             }
 
-            _ => {}
+            inst => debug_assert!(!inst.opcode().is_branch()),
         }
     }
 }

cranelift/codegen/src/ir/function.rs

@@ -315,7 +315,7 @@ impl FunctionStencil {
                 }
             }
 
-            _ => {}
+            inst => debug_assert!(!inst.opcode().is_branch()),
         }
     }
 

cranelift/codegen/src/verifier/mod.rs

@@ -1358,7 +1358,7 @@ impl<'a> Verifier<'a> {
                     }
                 }
             }
-            _ => {}
+            inst => debug_assert!(!inst.opcode().is_branch()),
         }
 
         match self.func.dfg.insts[inst].analyze_call(&self.func.dfg.value_lists) {

cranelift/frontend/src/frontend.rs

@@ -155,7 +155,7 @@ impl<'short, 'long> InstBuilderBase<'short> for FuncInstBuilder<'short, 'long> {
                 self.builder.declare_successor(*destination, inst);
             }
 
-            _ => {}
+            inst => debug_assert!(!inst.opcode().is_branch()),
         }
 
         if data.opcode().is_terminator() {