error[E0283]: type annotations needed for `Mask<_, LANES>`
  --> $DIR/issue-91614.rs:6:9
   |
LL |     let y = Mask::<_, _>::splat(false);
   |         ^   ------------------- type must be known at this point
   |
   = note: cannot satisfy `_: MaskElement`
   = help: the following types implement trait `MaskElement`:
             isize
             i8
             i16
             i32
             i64
note: required by a bound in `Mask::<T, LANES>::splat`
  --> $SRC_DIR/core/src/../../portable-simd/crates/core_simd/src/masks.rs:LL:COL
help: consider giving `y` an explicit type, where the type for type parameter `T` is specified
   |
LL |     let y: Mask<_, LANES> = Mask::<_, _>::splat(false);
   |          ++++++++++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0283`.