src/AstGen.zig                                                                     |   9 -
 src/Sema.zig                                                                       | 399 ++++++++++++++++++++++----------
 src/print_zir.zig                                                                  |  15 +-
 src/type.zig                                                                       |   5 +-
 test/behavior.zig                                                                  |   1 +
 test/behavior/empty_union.zig                                                      |  54 +++++
 test/behavior/error.zig                                                            |  62 ++++-
 test/behavior/optional.zig                                                         |  36 +++
 test/behavior/union.zig                                                            |  45 ++++
 test/cases/compile_errors/enum_with_0_fields.zig                                   |   7 -
 test/cases/compile_errors/invalid_error_union_payload_type.zig                     |  13 ++
 test/cases/compile_errors/invalid_optional_payload_type.zig                        |  13 ++
 test/cases/compile_errors/noreturn_struct_field.zig                                |  12 +
 test/cases/compile_errors/reify_type_for_exhaustive_enum_with_zero_fields.zig      |  18 --
 test/cases/compile_errors/reify_type_for_union_with_zero_fields.zig                |  17 --
 test/cases/compile_errors/runtime_cast_to_union_which_has_non-void_fields.zig      |   2 -
 test/cases/compile_errors/union_fields_with_value_assignments.zig                  |   7 -
 test/cases/compile_errors/union_noreturn_field_initialized.zig                     |  43 ++++
 test/cases/compile_errors/union_with_0_fields.zig                                  |   7 -
 test/cases/compile_errors/using_invalid_types_in_function_call_raises_an_error.zig |  11 -
 test/stage2/cbe.zig                                                                |   9 -
 21 files changed, 573 insertions(+), 212 deletions(-)