These operators are not defined in the metal namespace when the vector
operands are packed.
Fixed: tint:1121
Change-Id: I2e8f4302e08117ca41bac6c05fb24a70d1215740
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/62480
Kokoro: Kokoro <noreply+kokoro@google.com>
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>