[Migrated] Can not call function with sub-slice as argument

Issue automatically imported from old repo: https://github.com/EmbarkStudios/rust-gpu/issues/752
Old labels: t: enhancement,s: qptr may fix
Originally creatd by SiebenCorgie on 2021-09-13T18:50:11Z

When calling a function with a sub-slice of some other slice, the compiler throws a strange error:

Small example:

pub fn t1(main: &[f32]){
    let a = t2(&main[10..13]);
}

fn t2(sub: &[f32]) -> u32{
    1
}

throws

  error: Cannot cast between pointer types
    --> /.../rustup/toolchains/nightly-2021-08-27-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/const_ptr.rs:49:6
     |
  49 |     }
     |      ^
     |
     = note: from: *f32
     = note: to: *struct () {  }

  error: Cannot cast between pointer types
     --> /.../.rustup/toolchains/nightly-2021-08-27-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/metadata.rs:117:14
      |
  117 |     unsafe { PtrRepr { components: PtrComponents { data_address, metadata } }.const_ptr }
      |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      |
      = note: from: *[u8; 8]
      = note: to: *struct core::ptr::metadata::PtrComponents<[f32]> { *struct () {  }, u32 }

  error: Cannot cast between pointer types
     --> /.../.rustup/toolchains/nightly-2021-08-27-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/metadata.rs:117:14
      |
  117 |     unsafe { PtrRepr { components: PtrComponents { data_address, metadata } }.const_ptr }
      |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      |
      = note: from: *[u8; 8]
      = note: to: *struct *const [f32] { *[f32], u32 }

  error: Cannot offset a pointer to an arbitrary element
     --> /.../.rustup/toolchains/nightly-2021-08-27-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ptr/const_ptr.rs:235:18
      |
  235 |         unsafe { intrinsics::offset(self, count) }
      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is probably a similar problem like this, however, under different circumstances. If this is viewed as a duplicate, just close the Issue please.

Inizia riproducendo il piccolo esempio Rust nell’issue e confronta il comportamento con l’issue 329. È completato quando la chiamata a t2 con &main[10..13] compila senza gli errori segnalati di cast del puntatore e offset del puntatore.