Declare br_table otherwise ebb as predecessor (#551)

* Declare br_table otherwise ebb as predecessor (fixes #545)

lib/frontend/src/frontend.rs

@@ -141,7 +141,10 @@ impl<'short, 'long> InstBuilderBase<'short> for FuncInstBuilder<'short, 'long> {
                 None => {
                     // branch_destination() doesn't detect jump_tables
                     // If jump table we declare all entries successor
-                    if let InstructionData::BranchTable { table, .. } = data {
+                    if let InstructionData::BranchTable {
+                        table, destination, ..
+                    } = data
+                    {
                         // Unlike all other jumps/branches, jump tables are
                         // capable of having the same successor appear
                         // multiple times, so we must deduplicate.
@@ -159,8 +162,13 @@ impl<'short, 'long> InstBuilderBase<'short> for FuncInstBuilder<'short, 'long> {
                                 *dest_ebb,
                                 self.builder.position.basic_block.unwrap(),
                                 inst,
-                            )
+                            );
                         }
+                        self.builder.func_ctx.ssa.declare_ebb_predecessor(
+                            destination,
+                            self.builder.position.basic_block.unwrap(),
+                            inst,
+                        );
                     }
                 }
             }