lib/std/builtin.zig                                                              | 11 ++++
 src/Sema.zig                                                                     | 86 +++++++++++++++++++++++++++++++-
 test/cases/compile_errors/reify_type_for_tagged_union_with_extra_union_field.zig |  2 +-
 test/cases/safety/array slice sentinel mismatch non-scalar.zig                   | 21 ++++++++
 test/cases/safety/array slice sentinel mismatch vector.zig                       | 19 +++++++
 test/cases/safety/array slice sentinel mismatch.zig                              |  7 +--
 6 files changed, 140 insertions(+), 6 deletions(-)