AstGen: handle rl_ty_inst for mutable variables

src/AstGen.zig

@@ -2851,6 +2851,9 @@ fn varDecl(
             return &sub_scope.base;
         },
         .keyword_var => {
+            const old_rl_ty_inst = gz.rl_ty_inst;
+            defer gz.rl_ty_inst = old_rl_ty_inst;
+
             const is_comptime = var_decl.comptime_token != null or gz.force_comptime;
             var resolve_inferred_alloc: Zir.Inst.Ref = .none;
             const var_data: struct {
@@ -2875,6 +2878,7 @@ fn varDecl(
                         });
                     }
                 };
+                gz.rl_ty_inst = type_inst;
                 break :a .{ .alloc = alloc, .result_loc = .{ .ptr = alloc } };
             } else a: {
                 const alloc = alloc: {
@@ -2894,6 +2898,7 @@ fn varDecl(
                         });
                     }
                 };
+                gz.rl_ty_inst = .none;
                 resolve_inferred_alloc = alloc;
                 break :a .{ .alloc = alloc, .result_loc = .{ .inferred_ptr = alloc } };
             };

test/behavior/basic.zig

@@ -859,7 +859,6 @@ test "catch in block has correct result location" {
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
-    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
 
     const S = struct {
         fn open() error{A}!@This() {
@@ -887,3 +886,22 @@ test "labeled block with runtime branch forwards its result location type to bre
     };
     try expect(e == .b);
 }
+
+test "try in labeled block doesn't cast to wrong type" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+
+    const S = struct {
+        a: u32,
+        fn foo() anyerror!u32 {
+            return 1;
+        }
+    };
+    const s: ?*S = blk: {
+        var a = try S.foo();
+
+        _ = a;
+        break :blk null;
+    };
+    _ = s;
+}